Custom errors and callstack are not shown for my SharePoint 2010 installation

We all know that by default SharePoint will not show you the complete details of an error when it occurs. In SharePoint 2007 you could easily configure this by changing some values in the web.config of the appropriate web application. Basically you would change the callstack, customerrors mode and debug values.

Now in SharePoint 2010 you would expect the same behaviour but changing just the web application's web.config will not show you the complete error details. For this you must change the values in these web.config locations:

1. The web application
2. 14/Config
3. 14/Template/Layouts

You will want to change these properties:

customErrors mode="Off"
callstack="true" ... AllowPageLeveTrace="true"
compilation batch="false" debug="true"