I deployed some WSP's and and did Rollback with MSOCAF tool. Those wsp's are well tested and working good in other environments. After Rollback of those WSP's, When I am trying to retract it is giving "Microsoft.SharePoint.SPWebTemplateCollection cannot be deserialized because it does not have a public default constructor." Can anyone give me some guidance on this error.

Hi Kishore, If I understand correctly, you are using MICROSOFT SHAREPOINT ONLINE CODE ANALYSIS FRAMEWORK (MSOCAF) to submit customized solutions to Microsoft Online Service(MSO). If so, that is a MSO questions, I would suggest you to post the question in Microsoft Online Services(http://social.technet.microsoft.com/forums/en-US/category/microsoftonlineservices/) to get better support. Just a suggestion, you can try to re-submit the solutions without rollback, and then you should be able to retract them. Thanks, Jinchun ChenJin Chen - MSFT