There have been other posts saying the transfer file is too big. I thinks that's only from using the pdf file. You really need to transfer from the file ending in .tax2020. I don't know Mac but I think it doesn't always show you the file extension. @macuser_22
Try starting a new return and see if it finds any 2020 files to transfer from.
@MichelleLO here's another one
https://ttlc.intuit.com/community/taxes/discussion/2020-file-too-large-to-transfer-into-2021-turbo-t...
