Hi Asrujit. Yes, the database was upgraded to 10.5.1. I tested adding a new feature class, assigning privileges, registering as versioned, edited. No problem (I did not try enabling editing). After enabling editing to a few feature datasets, I found I couldn't edit. If I ran the 'Migrate Storage' tool - it allowed me to edit. After running the 'Migrate Storage Tool' on 2 feature datasets, with approximately 10 - 20 feature classes, I'm unable to open about 6 feature classes in ArcCatalog and ArcMap. I'm unable to do any Administration to the feature dataset as well now since some of the feature classes are broken.