Have you ever get the following error when you run Central Administration in SharePoint Server? I hope you haven’t yet and make yourself ready to fix this error for future Config Error There is a duplicate 'system.web.extensions/scri... defined Problem: I have installed SharePoint 2010 in a server and recently I got this error in my server when I tried to run central administration. I was stuck here to resolve this issue as it was my staging server and I can not re-build ......