How to display detailed Sharepoint errors for faster troubleshooting

Browse to the location where the web.config file is located for your web application.Usually C:\inetpub\wwwroot\wss\VirtualDirectories\80  (port number depend on where you have your web application)

Change these values from

<customErrors mode="On" />

And

CallStack="false"

to

<customErrors mode="Off" />

and

CallStack="true"

Save your web.config file. You will get detailed errors from now on.