The page cannot be displayed because an internal server error has occurred on server

Question

I ve installed website on my local machine using IIS 7 successfully  But when I ve deployed it on live server  I got the following error       The page cannot be displayed because an internal server error has occurred    Nothing else    Using the same IIS 7 on live and also set to have Detailed errors in Error Pages module  but still getting the same  What can be a reason   Thanks

User · Answer

In my case  setting httpErrors and the like in Web config did not help to identify the issue   Instead I did    Activate  Failed Request Tracing  for the website with the error  Configured a trace for HTTP errors 350-999  just in case   although I suspected 500  Called the erroneous URL again  Watched in the log folder    SystemDrive  inetpub logs FailedReqLogFiles  in my case   Opened one of the XML files in Internet Explorer    I then saw an entry with a detailed exception information  In my case it was        C  Websites example com www web config   592   Cannot add duplicate collection entry of type  mimeMap  with unique key attribute  fileExtension  set to   json    I now was able to resolve it and fix the error  After that I deactivated  Failed Request Tracing  again

User · Answer

I just got this error and it was caused by a duplicate static content MIME type in the web config  This error was being returned only on static files - eg images  css  js files were all saying this error  text by itself  no other html or text in the response    The way to debug this is to look in web config under static content  Here we have a json file extension loaded  This was required on IIS7 but will kill the app if used on IIS8 because json is now pre-loaded at the server level        lt staticContent gt           lt clientCache cacheControlMode  UseMaxAge  cacheControlMaxAge  30 00 00 00    gt           lt mimeMap fileExtension   json  mimeType  application json    gt       lt  staticContent gt    So solution is to remove any of these mimeType entries one at a time to confirm which are needed and which kill your app   Update  Actually the best solution was provided by a commenter here  You can remove and then add  which will always work regardless of whether it is already defined or not  Like this    lt remove fileExtension   json    gt    lt mimeMap fileExtension   json  mimeType  application json    gt

User · Answer

I think the best first approach is to make sure to turn on detailed error messages via your web config file  like this   lt configuration gt       lt system webServer gt           lt httpErrors errorMode  quot Detailed quot  gt  lt  httpErrors gt       lt  system webServer gt   lt  configuration gt   After doing this  you should get a more detailed error message from the server  In my particular case  the more detailed error pointed out that my  lt defaultDocument gt  section of the web config file was not allowed at the folder level where I d placed my web config   It said  This configuration section cannot be used at this path  This happens when the section is locked at a parent level  Locking is either by default  overrideModeDefault  quot Deny quot    or set explicitly by a location tag with overrideMode  quot Deny quot  or the legacy allowOverride  quot false quot    quot

User · Answer

I got the same error when I added the applicationinitialization module with lots of initializationpages and deployed it on Azure app  The issue turned out to be duplicate entries in my applicationinitialization module  I din t see any errors in the logs so it was hard to troubleshoot  Below is an example of the error code       lt configuration gt     lt system webServer gt       lt applicationInitialization doAppInitAfterRestart  true  skipManagedModules  true  gt         lt add initializationPage   init1 aspx call 2   gt         lt add initializationPage   init1 aspx call 2    gt       lt  applicationInitialization gt     lt  system webServer gt    Make sure there are no duplicate entries because those will be treated as duplicate keys which are not allowed and will result in  Cannot add duplicate collection entry  error for web config

User · Answer

I ended up on this page running Web Apps on Azure      The page cannot be displayed because an internal server error has occurred    We ran into this problem because we applicationInitialization in the web config   lt applicationInitialization     doAppInitAfterRestart  true      skipManagedModules  true  gt       lt add initializationPage   default aspx  hostName  myhost   gt   lt  applicationInitialization gt    If running on Azure  have a look at site slots  You should warm up the pages on a staging slot before swapping it to the production slot

User · Answer

Modify your web config to display the server error details    lt system web gt     lt customErrors mode  Off    gt   lt  system web gt    You may also need to remove comment out the follow httpErrors section     lt system webServer gt       lt httpErrors errorMode  Custom  gt         lt remove statusCode  404    gt         lt error statusCode  404  path   Error Error404  responseMode  ExecuteURL    gt         lt remove statusCode  500    gt         lt error statusCode  500  path   Error Error500  responseMode  ExecuteURL    gt         lt remove statusCode  403    gt         lt error statusCode  403  path   Error Error403  responseMode  ExecuteURL    gt       lt  httpErrors gt     lt  system webServer gt    From my experience if you directly have a server error  this may be caused from an assembly version mismatch    Check what is declared in the web config and the actual ddl in the bin folder s project

User · Answer

it seems it works after I commented this line in web config   lt compilation debug  true  targetFramework  4 5 2    gt

User · Answer

For those of you who hit this stackoverflow entry because it ranks high for the phrase      The page cannot be displayed because an internal server error has occurred    In my personal situation with this exact error message  I had turned on python 2 7 thinking I could use some python with my  NET API  I then had that exact error message when I attempted to deploy a vanilla version of the API or MVC from visual studio pro 2013  I was deploying to an azure cloud webapp   Hope this helps anyone with my same experience  I didn t even think to turn off python until I found this suggestion

User · Answer

I ve fixed it  I had the following section in web config    httpErrors existingResponse  PassThrough    When I remove it  I got a real error

[c#] The page cannot be displayed because an internal server error has occurred on server

Examples related to c#

Examples related to asp.net

Examples related to asp.net-mvc

Examples related to iis

Examples related to internal-server-error