Song error message when launching Reason

[ksniod]

I keep getting a message saying "Some Reason Suite songs were not closed properly" each time I launch Reason (11 on macOS Catalina).

Can anybody tell me how to get rid of this?

Some days ago (with 11.3.7 then11.3.8), Reason started to have tough problems with several songs and plugins and was crashing a lot (I don't know why).
It's now better (I don't know why neither, even if I uninstalled and reinstalled 11.3.6) but this is still showed at startup.

Apart from installing/reinstalling, I tried the offered "Export Song List" option and moved the song mentioned in the text file it produced, but no more success, the message still appears.
I also haven't found the error log or something I could just delete to clear the problem.

[ksniod]

I deleted the "TimeMachineExclusionList.txt" file from the Reason Suite folder in User Library>Application Support>Propellerhead Software and it did the trick (i deleted the same file in the Reason folder afterwards just in case).

(Reason Studios support made me delete all plugin caches, but with no change)