See setup Version 10.15.5
Saw a similar post suggesting that Dev Beta 5 fixes it
Still get error Processing.app” can’t be opened because Apple cannot check it for malicious software This software needs to be updated. Contact the developer for more information.
So when I downloaded it again, unpacked and executed it for the first time in the download folder it worked. The last time I unpacked it and moved it to the Applications folder first and then it didn’t work…Confusing, but anyway