brand new issue for me - cannot save layout file (originally created with 2018 pro) in 2018. i also created copy in 2020 pro and received same message.
i get message "The document “22 3.22.20 BID?Permit…” could not be saved.
I restarted macbook pro, then removed and reinstalled su 2018 pro and su 2020 pro.
Trying to save in the original file in the original folder. I may have discovered the problem. Since loading 2020 into computer, every file I open automatically opens in 2020. I now go to “get info” each time I open any Layout file and change the default to 2018, which resolves the issue. What would help is to have each file open in it’s original program automatically, unless I purposely update them. Thanks Dave! Any comments are appreciated.