This tip is for Windows SharePoint Services 2.0/3.0, SharePoint Portal Server 2003 and Microsoft Office SharePoint Server 2007 and may apply to SharePoint Foundation 2010 and SharePoint Server 2010.
Did you know that administrators can enable more verbose exception messages by editing the information in a web application’s web.config file? Usually when a site exception occurs there will be a generic description that an error has occurred. This is a security measure that makes it more difficult to gather information about the SharePoint site by creating exceptions on the site, which is one of the ways nefarious users use to attack sites. This does however make it more difficult to troubleshoot some issues for administrators. If the SharePoint site is public then it is best to extend and map the web application to another internal only web application that can have different web.config settings than the external web application. Then the internal site’s web.config can be updated using Notepad.exe or another text editor with the following to enable more verbose exception messages.
* Leave the other attributes to the defaults. E.g. MaxControls=”200”, DirectFileDependencies=”10”
More information on the customErrors attribute can be found here.
More information on the CallStack attribute can be found here. This article is for WSS 2.0, but still applies to WSS 3.0.
After making the changes save and close the web.config file. In IIS 6 and IIS 7 there is no need to recycle IIS or the application pool, the settings will be in effect right away.
Reproduce the steps that caused the exception and copy the resulting exception information from the error page and use a search engine like Bing to track down a resolution.
Remember to also edit the web.config back to the defaults when finished troubleshooting.