While importing the database afetr restoring to DB, i got the following error.
This shows that the DB version is different in source and destinations.
This can be the reason related to DB, as down grade is not possible.
also this can be a reason for the CRM instance installed.
as i have the following in my deplyment manager, both were in ms crm 2011.
This can happen if your dev server and uat does not have the correct rollups installed.
hope this will help.
Microsoft Dynamics CRM 2011 Administration Bible
Working with Microsoft Dynamics CRM 2011