Below is a list of steps to turn off SharePoint custom error messages so you can see the “true” ASP.NET error message along with the callstack/stack trace. I would recommend only making the following changes in a development environment – not production.
- Navigate to the site directory.
- Backup web.config.
- Open web.config.
- Switch Custom Errors off. Search for “customErrors” and set the value to “Off” instead of “On”. You can also set the value to “RemoteOnly” to troubleshoot a production issue.
- Enable CallStack. Search for “CallStack” and set the value to “true” instead of “false”.
- Save web.config.
