'Specified method is not supported' error when deleting SharePoint site
I was getting a “Specified method is not supported” error when I tried to delete some test sites in SharePoint 2010 today. I found a great link that gave several solutions to deletion errors. Issue #1 under this link is what I needed:
Even though I got an error executing the Upgrade-SPContentDatabase PowerShell command, it still fixed the problem with deleting the sites.