2010 to 2013 migration – Can’t get rid of MissingFeature warnings

I am in the process of migrating SharePoint 2010 to SharePoint 2013.

I already solved a huge amount of problems with “MissingFeature”, “MissingWebPart”, “MissingSetupFile”, “MissingAssembly” and so on.

I am down to 6 “MissingFeature” when I run a test on the database. My problem is that I can’t get rid of those warnings. When I query the Features table for the ID I can’t find it.

Unfortunately it is not an option to remove those features in the production system so I have to restore the content database in my test system and solve problems there.

I also tried Feature Admin 3 but the missing features aren’t showing up there either.

Is there any other way to get rid of those errors?