Troubleshooting Warning session start Cannot send session cache limiter - headers already sent

Question

i am getting    Warning  session start    function session-start   Cannot send session cache limiter - headers already sent  output started at  error  If i submit form data to a different file for processing  it works  But if i submit form data to the same page  it gives this error    please suggst   lt  DOCTYPE html PUBLIC  -  W3C  DTD XHTML 1 0 Transitional  EN   http   www w3 org TR xhtml1 DTD xhtml1-transitional dtd  gt   lt html xmlns  http   www w3 org 1999 xhtml  gt   lt head gt   lt meta http-equiv  Content-Type  content  text html  charset UTF-8    gt   lt link href  style css  rel  stylesheet  type  text css    gt   lt title gt Welcome lt  title gt     lt script type  text javascript  src  jquery js  gt  lt  script gt       lt script type  text javascript  gt    document  ready function                nav li   hover          function                    show its submenu                ul   this  slideDown 100                        function                    hide its submenu                ul   this  slideUp 100                                       lt  script gt    lt  head gt    lt body gt   lt table width  100   border  0  cellspacing  0  cellpadding  0  gt     lt tr gt       lt td class  header  gt  amp nbsp  lt  td gt     lt  tr gt     lt tr gt       lt td class  menu  gt  lt table align  center  cellpadding  0  cellspacing  0  width  80   gt       lt tr gt       lt td gt        lt ul id  nav  gt       lt li gt  lt a href     gt Catalog lt  a gt       lt ul gt  lt li gt  lt a href     gt Products lt  a gt  lt  li gt           lt li gt  lt a href     gt Bulk Upload lt  a gt  lt  li gt           lt  ul gt           lt div class  clear  gt  lt  div gt           lt  li gt         lt li gt  lt a href     gt Purchase   lt  a gt        lt  li gt       lt li gt  lt a href     gt Customer Service lt  a gt       lt ul gt           lt li gt  lt a href     gt Contact Us lt  a gt  lt  li gt           lt li gt  lt a href     gt CS Panel lt  a gt  lt  li gt        lt  ul gt                      lt div class  clear  gt  lt  div gt       lt  li gt       lt li gt  lt a href     gt All Reports lt  a gt  lt  li gt       lt li gt  lt a href     gt Configuration lt  a gt       lt ul gt   lt li gt  lt a href     gt Look and Feel  lt  a gt  lt  li gt            lt li gt  lt a href     gt Business Details lt  a gt  lt  li gt            lt li gt  lt a href     gt CS Details lt  a gt  lt  li gt            lt li gt  lt a href     gt Emaqil Template lt  a gt  lt  li gt            lt li gt  lt a href     gt Domain and Analytics lt  a gt  lt  li gt            lt li gt  lt a href     gt Courier lt  a gt  lt  li gt            lt  ul gt       lt div class  clear  gt  lt  div gt       lt  li gt       lt li gt  lt a href     gt Accounts lt  a gt       lt ul gt  lt li gt  lt a href     gt Ledgers lt  a gt  lt  li gt           lt li gt  lt a href     gt Account Details lt  a gt  lt  li gt           lt  ul gt            lt div class  clear  gt  lt  div gt  lt  li gt    lt  ul gt  lt  td gt  lt  tr gt  lt  table gt  lt  td gt     lt  tr gt     lt tr gt       lt td valign  top  gt  lt table width  80   border  0  align  center  cellpadding  0  cellspacing  0  gt         lt tr gt           lt td valign  top  gt  lt table width  100   border  0  cellspacing  0  cellpadding  2  gt             lt tr gt               lt td width  22   height  327  valign  top  gt  lt table width  100   border  0  cellspacing  0  cellpadding  2  gt                 lt tr gt                   lt td gt  amp nbsp  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  45  gt  lt strong gt - amp gt  Products lt  strong gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  61  gt  lt strong gt - amp gt  Categories lt  strong gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  48  gt  lt strong gt - amp gt  Sub Categories lt  strong gt  lt  td gt                   lt  tr gt               lt  table gt  lt  td gt               lt td width  78   valign  top  gt  lt table width  100   border  0  cellpadding  0  cellspacing  0  gt                 lt tr gt                   lt td gt  amp nbsp  lt  td gt                   lt  tr gt                 lt tr gt                   lt td gt                     lt table width  90   border  0  cellspacing  0  cellpadding  0  gt                       lt tr gt                         lt td width  26   gt  amp nbsp  lt  td gt                         lt td width  74   gt  lt h2 gt Manage Categories lt  h2 gt  lt  td gt                       lt  tr gt                     lt  table gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  30  gt  amp nbsp                    lt  td gt                   lt  tr gt                 lt tr gt                   lt td gt     lt  td gt                   lt  tr gt                    lt tr gt                   lt td gt                   lt table width  49   align  center  cellpadding  0  cellspacing  0  gt                   lt tr gt  lt td gt       lt  php                   if  isset   SESSION  error                                             echo   lt span id   error   gt  lt p gt       SESSION  error       lt  p gt  lt  span gt                         unset   SESSION  error                                           gt                    lt form action   lt  php echo   SERVER  PHP SELF      gt   method  post  enctype  multipart form-data  gt                    lt p gt                    lt label class  style4  gt Category Name lt  label gt                       amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp   lt input type  text  name  categoryname    gt  lt br   gt  lt br   gt                        lt label class  style4  gt Category Image lt  label gt  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp                        lt input type  file  name  image    gt  lt br   gt                        lt input type  hidden  name  MAX FILE SIZE  value  100000    gt                       lt br   gt   lt br   gt    lt input type  submit  id  submit  value  UPLOAD    gt                    lt  p gt                    lt  form gt                                    lt  php  session start     require  includes conn php      function is valid type  file           valid types   array  image jpg    image jpeg    image bmp    image gif    image png           if  in array  file  type     valid types            return 1       return 0     function showContents  array          echo   lt pre gt         print r  array        echo   lt  pre gt         TARGET PATH    images category     cname     POST  categoryname      image     FILES  image      cname   mysql real escape string  cname     image  name     mysql real escape string  image  name       TARGET PATH     image  name     if    cname           image  name                     SESSION  error      All fields are required        header  Location  managecategories php         exit      if   is valid type  image             SESSION  error      You must upload a jpeg  gif  or bmp        header  Location  managecategories php         exit         if  file exists  TARGET PATH             SESSION  error      A file with that name already exists        header  Location  managecategories php         exit       if  move uploaded file  image  tmp name     TARGET PATH              sql    insert into Categories  CategoryName  FileName  values    cname         image  name                 result   mysql query  sql  or die   Could not insert data into DB      mysql error        header  Location  mangaecategories php         exit      else               SESSION  error      Could not upload file   Check read write persmissions on the directory        header  Location  mangagecategories php         exit        gt     Here is the code for Display   lt  php                     require  includes conn php                         sql    select CategoryID  CategoryName  FileName  Status from Categories                     result   mysql query  sql  or die   Could not access DB      mysql error                        while   row   mysql fetch assoc  result                                            echo   lt table border  0  cellpadding  10  gt                                              echo   lt tr gt  lt td gt    lt  td gt  lt td gt Category ID lt  td gt  lt td gt Category Name lt  td gt  lt td gt Status lt  td gt  lt td gt Edit lt  td gt  lt td gt Delete lt  td gt  lt  tr gt                                             echo   lt tr gt  lt td gt   lt img src   images      row  FileName         alt        gt   lt  td gt                                            echo   lt td gt     row  CategoryID       lt  td gt                                                echo   lt td gt     row  CategoryName       lt  td gt                                                echo   lt td gt     row  Status      lt  td gt                                                echo   lt td gt   lt a href   edit php CategoryID     row  id       gt  Edit  lt  a gt  lt  td gt                                                echo   lt td gt   lt a href   delete php CategoryID     row  id       gt  Edit  lt  a gt  lt  td gt                                             echo   lt  tr gt   lt  table gt                                        gt    Nothing is happening here  Please suggest

User · Answer

For others who may run across this - it can also occur if someone carelessly leaves trailing spaces from a php include file. Example:

 <?php 
    require_once('mylib.php');
    session_start();
 ?>

In the case above, if the mylib.php has blank spaces after its closing ?> tag, this will cause an error. This obviously can get annoying if you've included/required many files. Luckily the error tells you which file is offending.

HTH

User · Answer

I had a website transferring from one host to another  it seemed to work fine on the old host but a few pages on the new host threw the error Warning  session start    Cannot send session cache limiter - headers already sent while I always kept the     lt php session start      at the top of the page no spaces and nothing inserted before  it really bugged me that I stared every page with the session opening  and it worked on some pages and run through a bug on others I picked the pages that had the problems  backed them up  created new blank pages and simply copied and pasted the code as is  saved and uploaded and boom  problem gone   this is something you guys may need to consider  it may have been the encoding of the page  or something  not sure the exact source of the problem  but here is a fix to look at in case you guys run into a similar problem  cheers

User · Answer

I was able to solve similar Warning  session start    Cannot send session cache limiter - headers already sent by just removing a space in front of the  lt  php tag   It worked

User · Answer

This should solve your problem  session start   should be called before any character is sent back to the browser  In your case  HTML and blank lines were sent before you called session start    Documentation here   To further explain your question of why it works when you submit to a different page  that page either do not use session start   or calls session start   before sending any character back to the client  This page on the other hand was calling session start   much later when a lot of HTML has been sent back to the client  browser     The better way to code is to have a common header file that calls connects to MySQL database  calls session start   and does other common things for all pages and include that file on top of each page like below   include  header php     This will stop issues like you are having as also allow you to have a common set of code to manage across a project  Something definitely for you to think about I would suggest after looking at your code    lt  php session start                     if  isset   SESSION  error                                             echo   lt span id   error   gt  lt p gt       SESSION  error       lt  p gt  lt  span gt                         unset   SESSION  error                                           gt                    lt form action   lt  php echo   SERVER  PHP SELF      gt   method  post  enctype  multipart form-data  gt                    lt p gt                    lt label class  style4  gt Category Name lt  label gt                       amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp   lt input type  text  name  categoryname    gt  lt br   gt  lt br   gt                        lt label class  style4  gt Category Image lt  label gt  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp                        lt input type  file  name  image    gt  lt br   gt                        lt input type  hidden  name  MAX FILE SIZE  value  100000    gt                       lt br   gt   lt br   gt    lt input type  submit  id  submit  value  UPLOAD    gt                    lt  p gt                    lt  form gt                                    lt  php    require  includes conn php      function is valid type  file           valid types   array  image jpg    image jpeg    image bmp    image gif    image png           if  in array  file  type     valid types            return 1       return 0     function showContents  array          echo   lt pre gt         print r  array        echo   lt  pre gt         TARGET PATH    images category     cname     POST  categoryname      image     FILES  image      cname   mysql real escape string  cname     image  name     mysql real escape string  image  name       TARGET PATH     image  name     if    cname           image  name                     SESSION  error      All fields are required        header  Location  managecategories php         exit      if   is valid type  image             SESSION  error      You must upload a jpeg  gif  or bmp        header  Location  managecategories php         exit         if  file exists  TARGET PATH             SESSION  error      A file with that name already exists        header  Location  managecategories php         exit       if  move uploaded file  image  tmp name     TARGET PATH              sql    insert into Categories  CategoryName  FileName  values    cname         image  name                 result   mysql query  sql  or die   Could not insert data into DB      mysql error        header  Location  mangaecategories php         exit      else               SESSION  error      Could not upload file   Check read write persmissions on the directory        header  Location  mangagecategories php         exit        gt

User · Answer

The answer is above by Ross   Firstly  putting session start   as the first line of code will mean that you cannot deserialise any objects correctly into session variables   The reason for getting this issue is 99  likely to be trailing spaces at the end of your include files  yes - I know it sounds unlikely but just try it    The offending file is in the error message   I wanted to back up Ross answer which worked for me but this site is counter intuitive     IGNORE the nonsense answers   Remove the trailing spaces  newlines etc    and all will be well   ROSS knows what he is talking about  Putting session start   at the top of your file DOES work but it isnt the correct solution

User · Answer

Check any extra space before php tag

User · Answer

Generally this error arise when we send header after echoing or printing  If this error arise on a specific page then make sure that page is not echoing anything before calling to start session     Example of Unpredictable Error     lt  php   a white-space before  lt  php also send for output and arise error session start    session regenerate id       your page content   One more example    lt  php includes  functions php     gt   lt  -- This new line will also arise error -- gt   lt  php session start    session regenerate id       your page content   Conclusion  Do not output any character before calling session start   or header   functions not even a white-space or new-line

User · Answer

use session start   at the top of the page     for more details please read the link session start

User · Answer

use     ob start    before  session start    at top of your page like this   lt  php ob start    session start

User · Answer

This started for me when I redirected my site to https     for SSL Certificate   From my experience with this issue  the session start   had to be before the browser saw any HTML code  For my example  I was using session start   in nav php to determine the options of the navigation bar  I ended up placing session start   right after the php comments in the index php file and every page which called nav php  I was able to keep the php comments before session start   but could not keep the HTML comments above the php

User · Answer

You will find I have added the session start   at the very top of the page  I have also removed the session start   call later in the page  This page should work fine    lt  php session start      gt   lt  DOCTYPE html PUBLIC  -  W3C  DTD XHTML 1 0 Transitional  EN   http   www w3 org TR xhtml1 DTD xhtml1-transitional dtd  gt   lt html xmlns  http   www w3 org 1999 xhtml  gt   lt head gt   lt meta http-equiv  Content-Type  content  text html  charset UTF-8    gt   lt link href  style css  rel  stylesheet  type  text css    gt   lt title gt Welcome lt  title gt     lt script type  text javascript  src  jquery js  gt  lt  script gt       lt script type  text javascript  gt    document  ready function                nav li   hover          function                    show its submenu                ul   this  slideDown 100                        function                    hide its submenu                ul   this  slideUp 100                                       lt  script gt    lt  head gt    lt body gt   lt table width  100   border  0  cellspacing  0  cellpadding  0  gt     lt tr gt       lt td class  header  gt  amp nbsp  lt  td gt     lt  tr gt     lt tr gt       lt td class  menu  gt  lt table align  center  cellpadding  0  cellspacing  0  width  80   gt       lt tr gt       lt td gt        lt ul id  nav  gt       lt li gt  lt a href     gt Catalog lt  a gt       lt ul gt  lt li gt  lt a href     gt Products lt  a gt  lt  li gt           lt li gt  lt a href     gt Bulk Upload lt  a gt  lt  li gt           lt  ul gt           lt div class  clear  gt  lt  div gt           lt  li gt         lt li gt  lt a href     gt Purchase   lt  a gt        lt  li gt       lt li gt  lt a href     gt Customer Service lt  a gt       lt ul gt           lt li gt  lt a href     gt Contact Us lt  a gt  lt  li gt           lt li gt  lt a href     gt CS Panel lt  a gt  lt  li gt        lt  ul gt                      lt div class  clear  gt  lt  div gt       lt  li gt       lt li gt  lt a href     gt All Reports lt  a gt  lt  li gt       lt li gt  lt a href     gt Configuration lt  a gt       lt ul gt   lt li gt  lt a href     gt Look and Feel  lt  a gt  lt  li gt            lt li gt  lt a href     gt Business Details lt  a gt  lt  li gt            lt li gt  lt a href     gt CS Details lt  a gt  lt  li gt            lt li gt  lt a href     gt Emaqil Template lt  a gt  lt  li gt            lt li gt  lt a href     gt Domain and Analytics lt  a gt  lt  li gt            lt li gt  lt a href     gt Courier lt  a gt  lt  li gt            lt  ul gt       lt div class  clear  gt  lt  div gt       lt  li gt       lt li gt  lt a href     gt Accounts lt  a gt       lt ul gt  lt li gt  lt a href     gt Ledgers lt  a gt  lt  li gt           lt li gt  lt a href     gt Account Details lt  a gt  lt  li gt           lt  ul gt            lt div class  clear  gt  lt  div gt  lt  li gt    lt  ul gt  lt  td gt  lt  tr gt  lt  table gt  lt  td gt     lt  tr gt     lt tr gt       lt td valign  top  gt  lt table width  80   border  0  align  center  cellpadding  0  cellspacing  0  gt         lt tr gt           lt td valign  top  gt  lt table width  100   border  0  cellspacing  0  cellpadding  2  gt             lt tr gt               lt td width  22   height  327  valign  top  gt  lt table width  100   border  0  cellspacing  0  cellpadding  2  gt                 lt tr gt                   lt td gt  amp nbsp  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  45  gt  lt strong gt - amp gt  Products lt  strong gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  61  gt  lt strong gt - amp gt  Categories lt  strong gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  48  gt  lt strong gt - amp gt  Sub Categories lt  strong gt  lt  td gt                   lt  tr gt               lt  table gt  lt  td gt               lt td width  78   valign  top  gt  lt table width  100   border  0  cellpadding  0  cellspacing  0  gt                 lt tr gt                   lt td gt  amp nbsp  lt  td gt                   lt  tr gt                 lt tr gt                   lt td gt                     lt table width  90   border  0  cellspacing  0  cellpadding  0  gt                       lt tr gt                         lt td width  26   gt  amp nbsp  lt  td gt                         lt td width  74   gt  lt h2 gt Manage Categories lt  h2 gt  lt  td gt                       lt  tr gt                     lt  table gt  lt  td gt                   lt  tr gt                 lt tr gt                   lt td height  30  gt  amp nbsp                    lt  td gt                   lt  tr gt                 lt tr gt                   lt td gt     lt  td gt                   lt  tr gt                    lt tr gt                   lt td gt                   lt table width  49   align  center  cellpadding  0  cellspacing  0  gt                   lt tr gt  lt td gt       lt  php                   if  isset   SESSION  error                                             echo   lt span id   error   gt  lt p gt       SESSION  error       lt  p gt  lt  span gt                         unset   SESSION  error                                           gt                    lt form action   lt  php echo   SERVER  PHP SELF      gt   method  post  enctype  multipart form-data  gt                    lt p gt                    lt label class  style4  gt Category Name lt  label gt                       amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp   lt input type  text  name  categoryname    gt  lt br   gt  lt br   gt                        lt label class  style4  gt Category Image lt  label gt  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp  amp nbsp                        lt input type  file  name  image    gt  lt br   gt                        lt input type  hidden  name  MAX FILE SIZE  value  100000    gt                       lt br   gt   lt br   gt    lt input type  submit  id  submit  value  UPLOAD    gt                    lt  p gt                    lt  form gt                                    lt  php   require  includes conn php      function is valid type  file           valid types   array  image jpg    image jpeg    image bmp    image gif    image png           if  in array  file  type     valid types            return 1       return 0     function showContents  array          echo   lt pre gt         print r  array        echo   lt  pre gt         TARGET PATH    images category     cname     POST  categoryname      image     FILES  image      cname   mysql real escape string  cname     image  name     mysql real escape string  image  name       TARGET PATH     image  name     if    cname           image  name                     SESSION  error      All fields are required        header  Location  managecategories php         exit      if   is valid type  image             SESSION  error      You must upload a jpeg  gif  or bmp        header  Location  managecategories php         exit         if  file exists  TARGET PATH             SESSION  error      A file with that name already exists        header  Location  managecategories php         exit       if  move uploaded file  image  tmp name     TARGET PATH              sql    insert into Categories  CategoryName  FileName  values    cname         image  name                 result   mysql query  sql  or die   Could not insert data into DB      mysql error        header  Location  mangaecategories php         exit      else               SESSION  error      Could not upload file   Check read write persmissions on the directory        header  Location  mangagecategories php         exit        gt

User · Answer

In my case I had to set the file encoding without BOM

User · Answer

I had the same issue  but my solution wasn t as obvious as the suggested ones  It turned out that my php-file was written in UTF-8  which caused issues  I copy pasted the content of the entire file into a new php-file  Notepad   tells me this is written in ANSI rather than UTF-8   and now it work flawlessly

User · Answer

replace session start    with  session start    in your code

User · Answer

Just replace session start with this   if   session id    amp  amp   headers sent         session start          You can put it anywhere  even at the end    Works fine for me    SESSION is accessible as well

[php] Troubleshooting "Warning: session_start(): Cannot send session cache limiter - headers already sent"

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