What software are you using?

Is there any other message along with that error?

Proseries 2022. When I try to transfer 1120S from 22 to 23 it says: "Legacy format files are deprecated. If you have any issues transferring this file,open and save the return in the previous year's ProSeries and try again".

Id open the file in the 2022 program, and SAVE AS and give it a new file name, then try transferring the newly named file.

i am using proseries 2023  and the error is 604