Looks like a common theme today, see if my answer in this thread helps at all
https://proconnect.intuit.com/community/proseries-tax-discussions/discussion/error-code-54/00/256397

I had the same problem and did everything.  Finally had to save data files elsewhere and reinstall without returns and the restore the data files from the saved ones.  Very frustrating and took 4 hours out of my day whole trouble shooting 

REPAIR UPDATES has worked for other people