Error while executing the SharePoint 2010 PowerShell cmdlet Mount-SPContentDatabase: “Exception of type ‘Microsoft.SharePoint.Upgrade.SPUpgradeException’ was thrown.”

Mount-SPContentDatabase : Exception of type 'Microsoft.SharePoint.Upgrade.SPUpgradeException' was thrown.
At D:TempAttach_OldContentDBs_DoIt.ps1:63 char:28
+              Mount-SPContentDatabase <<<<  -WebApplication $webapp -Name $thisdb
    + CategoryInfo          : InvalidData: (Microsoft.Share...ContentDatabase:SPCmdletMountContentDatabase) [Mount-SPContentDatabase], SPUpg
   radeException
    + FullyQualifiedErrorId : Microsoft.SharePoint.PowerShell.SPCmdletMountContentDatabase

Have a look into the SQL Server Management Studio. – The content database is read only. That’s the problem Smile