Failure Cause: The database schema version is less than the minimum backwards compatibility schema version that is supported for this component. To resolve this problem upgrade this database.

If you get this error, go to PowerShell Command, and type the following:

(get-spserver $env:computername).NeedsUpgrade

then, if it false, run the following from VSS Administrative command prompt:

PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures

SharePoint 2010 website requires you to log in - error

add <computer name\server>\users Read & Execute, List Folder Contents and Read permissions.