Transferred all 2020 1040 date files to 2021 organizer Homebase without issue.  Did normal work to update the org files for address changes, etc., and add certain forms in the organizer for clients with new business or home sales in 2021.  Issued all organizers by email or paper mailing.  In the 1040 Homebase went to transfer all client files from 2021 org to 2021 1040 files.

Most files transferred but about 17% would not transfer.  Transfer error message said "unknown error unable to transfer(900)".  Intuit says it has no problem in the program and suggested Windows problem and then antivurus software problem.  Windows possible problem was eliminated and the same with antivirus possible problem.

The only common factor I can see in the untransferred files is that all contain at least one partnership and/or Subchapter S K-1 input worksheet.

Intuit said ask you guys.