Could not load the Web.config configuration file. Check the file for any malformed XML elements, and try again. The following error occurred: The given key was not present in the dictionary.

Problem Description:

I tried to debug SharePoint project in Visual Studio 2010. I found error where deploying project/solution is fine, but debugging doesn’t work. I saw an error alert with the text:

“Could not load the Web.config configuration file. Check the file for any malformed XML elements, and try again. The following error occurred: The given key was not present in the dictionary.”

The Web.config doesn’t have any error. One thing to check into is the configuration of alternate access mappings in Central Administration.

For debugging to work, the Site URL property of our SharePoint project must match the URL of the Default zone for your web application.

Resolution:

Step 1: Go to Central Administration

Step 2: System Setting

Step 3: Configure alternate access mappings

Step 4: Edit public URLs

Step 4: Set Default URL same as Visual Studio

(In this case make it as http://SiteName:20103)

Product applies to:

·     SharePoint Server 2010

·     SharePoint Foundation 2010