CustomErrors mode Off

Question

I get an error everytime I upload my webapp to the provider  Because of the customErrors mode  all I see is the default  Runtime error  message  instructing me to turn off customErrors to view more about the error   Exasperated  I ve set my web config to look like this    lt  xml version  1 0   gt   lt configuration gt       lt system web gt           lt customErrors mode  Off   gt       lt  system web gt   lt  configuration gt    And still  all I get is the stupid remote errors page with no useful info on it  What else can I do to turn customErrors OFF

User · Answer

In the interests of adding more situations to this question (because this is where I looked because I was having the exact same problem), here's my answer:

In my case, I cut/pasted the text from the generic error saying in effect if you want to see what's wrong, put

<system.web>
   <customErrors mode="Off"/>
</system.web>

So this should have fixed it, but of course not! My problem was that there was a <system.web> node several lines above (before a compilation and authentication node), and a closing tag </system.web> a few lines below that. Once I corrected this, OK, problem solved. What I should have done is copy/pasted only this line:

<customErrors mode="Off"/>

This is from the annals of Stupid Things I Keep Doing Over and Over Again, in the chapter entitled "Copy and Paste Your Way to Destruction".

User · Answer

That s really strange  I got this error and after rebooting of my server it disappeared

User · Answer

Off  is case-sensitive   Check if the  O  is in uppercase in your web config file  I ve suffered that a few times  as simple as it sounds

User · Answer

You can also try bringing up the website in a browser on the server machine   I don t do a lot of ASP NET development  but I remember the custom errors thing has a setting for only displaying full error text on the server  as a security measure

User · Answer

You can generally find more information regarding the error in the Event Viewer  if you have access to it  Your provider may also have prevented custom errors from being displayed at all  by either overriding it in their machine config  or setting the retail attribute to true  http   msdn microsoft com en-us library ms228298 VS 80  aspx

User · Answer

Is this web app set below any other apps in a website s directory tree   Check any parent web config files for other settings  if any   Also  make your your directory is set as an application directory in IIS

User · Answer

This has been driving me insane for the past few days and couldn t get around it but have finally figured it out   In my machine config file I had an entry under  lt system web gt     lt deployment retail  true    gt    This seems to override any other customError settings that you have specified in a web config file  so setting the above entry to    lt deployment retail  false    gt    now means that I can once again see the detailed error messages that I need to   The machine config is located at  32-bit   windir  Microsoft NET Framework  version  config machine config   64-bit   windir  Microsoft NET Framework64  version  config machine config    Hope that helps someone out there and saves a few hours of hair-pulling

User · Answer

For me it was an error higher up in the web config above the system web      the file blah didn t exist so it was throwing an error at that point  Because it hadn t yet got to the System Web section yet it was using the server default setting for CUstomErrors  On

User · Answer

We had this issue and it was due to the IIS user not having access to the machine config on the web server

User · Answer

Do you have any special character like        in your web config  If so make sure that the encoding is set to utf-8

User · Answer

It s also possible in some cases that web config is not formatted correctly  In that case you have to go through it line by line before  will work  Often  rewrite rules are the culprit here

User · Answer

Having tried all the answers here  it turned out that my Application Error method had this   Server ClearError    Response Redirect   Home Error      Removing these lines and setting fixed the problem   The client still got redirected to the error page with customErrors  On

User · Answer

I have had the same problem  and I went through the Event viewer application log where it clearly mention due to which exception this is happened   In my case exception was as below     Exception information    Exception type  HttpException  Exception message  The target principal name is incorrect   Cannot generate SSPI context  at System Web HttpApplicationFactory EnsureAppStartCalledForIntegratedMode HttpContext context  HttpApplication app  at System Web HttpApplication RegisterEventSubscriptionsWithIIS IntPtr appContext  HttpContext context  MethodInfo   handlers  at System Web HttpApplication InitSpecial HttpApplicationState state  MethodInfo   handlers  IntPtr appContext  HttpContext context  at System Web HttpApplicationFactory GetSpecialApplicationInstance IntPtr appContext  HttpContext context  at System Web Hosting PipelineRuntime InitializeApplication IntPtr appContext   The target principal name is incorrect   Cannot generate SSPI context    I have just updated my password in application pool and it works for me

User · Answer

I tried most of the stuff described here  I was using VWD and the default web config file contained        lt customErrors mode  RemoteOnly  defaultRedirect  GenericErrorPage htm  gt           lt error statusCode  403  redirect  NoAccess htm    gt           lt error statusCode  404  redirect  FileNotFound htm    gt       lt  customErrors gt    I changed mode  RemoteOnly  to mode  Off   Still no joy  I then used IIS manager  properties  ASP Net Tab  Edit configuration  then chose the CustomeErrors tab  This still showed RemoteOnly  I changed this to Off and finally I could see the detailed error messages   When I inspected the web config I saw that there were two CustomErrors nodes in the system web  and I have just noticed that the second entry  the one I was changing was inside a comment   So try not to use notepad to inspect web config on a remote server   However  if you use the IIS edit configuration stuff it will complain about errors in the web config  Then you can rule out all of the answers that say  is there an XML syntax error in your web config

User · Answer

If you re using the MVC preview 4  you could be experiencing this because you re using the HandleErrorAttribute   The behavior changed in 5 so that it doesn t handle exceptions if you turn off custom errors

User · Answer

I had the same issue but found resolve in a different way    -  What I did was  I opened Advanced Settings for the Application Pool in IIS Manager   There I set Enable 32-Bit Applications to True

User · Answer

It may not be IIS  I went through all of the answers on this page  as well as several more  None of them solved our issue  BUT they are good things to check and WILL cause problems  SO check those first  If you re still pulling your hair out  and you re using PHP  check your PHP settings  What fixed it for me was to edit our php ini file and specify  display errors  On  I also set  display startup errors  On  just for good measure  That fixed the problem  and our real issue turned out to be a missed comma that was missed during dev to stage migration  I realize this page was linked to asp net  which we were ALSO using  and this is not an asp net issue  but when you search for these errors  this page comes up and has some good info for fixing most common problems  just not our specific issue  The config changes did fix it  and then we could concentrate on our asp net files

User · Answer

If you re still getting that page  it s likely that it s blowing up before getting past the Web Config  Make sure that ASP Net has permissions it needs to things like the  Net Framework folders  the IIS Metabase  etc   Do you have any way of checking that ASP Net is installed correctly and associated in IIS correctly   Edit   After Greg s comment it occured to me I assumed that what you posted was your entire very minimal web config  is there more to it  If so can you post the entire web config

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Actually  what I figured out while hosting my web app is the the code you developed on your local Machine is of higher version than the hosting company offers you  If you have admin privileges you may be able to change the Microsoft ASP NET version support under web hosting setting

User · Answer

We also ran into this error and in our case it was because the application pool user did not have permissions to the web config file anymore  The reason it lost its permissions  everything was fine before  was because we had a backup of the site in a rar file and I dragged a backup version of the web config from the rar into the site  This seems to have removed all permissions to the web config file except for me  the logged on user    It took us a while to figure this out because I repeatedly checked permissions on the folder level  but never on the file level

User · Answer

If you are doing a config transform  you may also need to remove the following line from the relevant web config file    lt compilation xdt Transform  RemoveAttributes debug     gt

User · Answer

You can also try bringing up the website in a browser on the server machine   I don t do a lot of ASP NET development  but I remember the custom errors thing has a setting for only displaying full error text on the server  as a security measure

User · Answer

My problem was that i had this defined in my web config   lt httpErrors errorMode  Custom  existingResponse  Replace  gt     lt remove statusCode  404    gt     lt remove statusCode  500    gt     lt error statusCode  404  responseMode  ExecuteURL  path   Error NotFound    gt     lt error statusCode  500  responseMode  ExecuteURL  path   Error Internal    gt   lt  httpErrors gt

User · Answer

I also had this problem  but when using Apache and mod mono  For anyone else in that situation  you need to restart Apache after changing web config to force the new version to be read

User · Answer

The one answer that actually worked to fix this I found here  https   stackoverflow com a 18938991 550975  Just add this to your web config    lt configuration gt       lt system webServer gt         lt httpErrors existingResponse  PassThrough   gt       lt  system webServer gt     lt configuration gt

User · Answer

Also make sure you re editing web config and not website config  as I was doing

User · Answer

For Sharepoint 2010 applications  you should also edit C  Program Files Common Files Microsoft Shared Web Server Extensions 14 TEMPLATE LAYOUTS web config and define  lt customErrors mode  Off    gt

User · Answer

Try restarting the application  creating an app offline htm than deleting it will do  and if you still get the same error message  make sure you ve only declared customErrors once in the web config  or anything like that  Errors in the web config can have some weird impact on the application

User · Answer

I have had the same problem  and the cause was that IIS was running ASP NET 1 1  and the site required  NET 2 0   The error message did nothing but throw me off track for several hours

User · Answer

This has been driving me insane for the past few days and couldn t get around it but have finally figured it out   In my machine config file I had an entry under  lt system web gt     lt deployment retail  true    gt    This seems to override any other customError settings that you have specified in a web config file  so setting the above entry to    lt deployment retail  false    gt    now means that I can once again see the detailed error messages that I need to   The machine config is located at  32-bit   windir  Microsoft NET Framework  version  config machine config   64-bit   windir  Microsoft NET Framework64  version  config machine config    Hope that helps someone out there and saves a few hours of hair-pulling

User · Answer

Make sure you add       right after the system web  I put it toward the end of the node and didn t work

User · Answer

I tried most of the stuff described here  I was using VWD and the default web config file contained        lt customErrors mode  RemoteOnly  defaultRedirect  GenericErrorPage htm  gt           lt error statusCode  403  redirect  NoAccess htm    gt           lt error statusCode  404  redirect  FileNotFound htm    gt       lt  customErrors gt    I changed mode  RemoteOnly  to mode  Off   Still no joy  I then used IIS manager  properties  ASP Net Tab  Edit configuration  then chose the CustomeErrors tab  This still showed RemoteOnly  I changed this to Off and finally I could see the detailed error messages   When I inspected the web config I saw that there were two CustomErrors nodes in the system web  and I have just noticed that the second entry  the one I was changing was inside a comment   So try not to use notepad to inspect web config on a remote server   However  if you use the IIS edit configuration stuff it will complain about errors in the web config  Then you can rule out all of the answers that say  is there an XML syntax error in your web config

User · Answer

I have just dealt with similar issue  In my case the default site asp net version was 1 1 while i was trying to start up a 2 0 web app  The error was pretty trivial  but it was not immediately clear why the custom errors would not go away  and runtime never wrote to event log   Obvious fix was to match the version in Asp Net tab of IIS

[asp.net] CustomErrors mode="Off"

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