Are you sure they were CS6 files to start? Direct conversion of legacy files can sometimes do strange things.
I'd recommend exporting to .idml and then do whatever you need to fix them. See Remove minor corruption by exporting
Are you sure they were CS6 files to start? Direct conversion of legacy files can sometimes do strange things.
I'd recommend exporting to .idml and then do whatever you need to fix them. See Remove minor corruption by exporting