I have performed a database attach migration and, as expected, received errors in the log like:
[STSADM] [SPContentDatabaseSequence] [ERROR] [1/16/2013 8:46:44 AM]: Found a missing feature Id = [d56f0d2d-0107-424d-aa0d-7120329a23e6]
[STSADM] [SPContentDatabaseSequence] [ERROR] [1/16/2013 8:46:45 AM]: The feature with Id d56f0d2d-0107-424d-aa0d-7120329a23e6 is referenced in the database [WSS_Content], but is not installed on the current farm. The missing feature may cause upgrade to fail. Please install any solution which contains the feature and restart upgrade if necessary.
I removed the features from the database using (for 3 offending Features):
DELETE FROM WSS_Content.dbo.Features WHERE FeatureId = 'd56f0d2d-0107-424d-aa0d-7120329a23e6'
I'm still getting the generic File Not Found error page and don't know what to do next?