Upgrade from SP2010 to SP2013: Missing feature error

Hello,

We are trying to upgrade from SP 2010 to SP13. We have attached the database from SP 2010 prod environment to the SP13 test environment.

We have added and installed all the solutions. When we run the Test-SPContentDatabase command, we get MissingFeature error for all the features in our solution. If we run command to install the feature, it gives an error that the feature is already installed in the farm.

All the features are visible in the 15 hive folder. We are unable to figure out why its giving an error.

Any help on this is appreciated.

Thanks and Regards,

Neha