[Solved] Catalina Compatibility issues?

[RoryOF]

Following a move across from a PC laptop (Dell) to an Apple iMac, I am unable to install/use under OS X "Catalina" (I am using a brand new iMac 27"). It downloads OK, but refuses to "Open", giving the following error message: "macOS cannot verify that this app is free from malware." I have tried control-click open in the Go - Applications menu in Finder, same result. Most frustrating, as this has been my main software for nigh on 20 years now. I really don't fancy learning a new programme, so I am hoping someone here can help? My Firewall is "Off", but I do run Malwarebytes. However, I turned this off whilst downloading as I know it can cause problems.

[RoryOF]

This is due to the Gatekeeper application that Apple is supplying with your computer.
For a solution read Q05/A05 in the Mac FAQ

[MartinBrown]

Thanks, but as I mentioned, I have tried that (Go, Applications, Control-click). Still no go.

[RoryOF]

Then you will have to wait for advice from a Mac user. My understanding from Forum informations is that the Gatekeeper method works with Catalina, but not having a Mac I cannot say from personal experience.

[MartinBrown]

Thanks. Your post made me go back and fiddle with Gatekeeper. Success!