Turn on the yellow errorpage and callstack in SharePoint

Have you also got the very annoying and rather useless error screen saying "Error  - An unexpected error has occurred".

Here is how you can turn this custom errorpage off and display the regular "yellow-screen-of-death" errorpage with a more explanatory errormessage and callstack:

Edit the web.config of your webapplication located in C:\inetpub\wwwroot\wss\VirtualDirectories\80 (80 is the port of which your webapplication is listening. If you have more than one webapplication running on the same server, this may differ).

You will have to change to lines:

1) Turn on the callstack - set CallStack to true in the SafeMode element

<SafeMode MaxControls="200" CallStack="true" DirectFileDependencies="10" TotalFileDependencies="50" AllowPageLevelTrace="false">

2) Turn off custom errors - in the customErrors-element set mode to Off

<customErrors mode="Off" />

Save, reload the page, and be happy to see the yellow-screen-of-death page. :-)

 See also Using the ULS log viewer to search for a correlation id