Confirmed that it's not a permissions error on my Mac, so not quite sure what's causing it.
It is something related to that though.
That's a message that the OS give when you try to open an app that is from a third party and it's not recognized and quarantined, is a security problem that happen when the OS is trying to run the executable of an app that's not officially developed from Apple or from a third party that's not authorized ( though I read of a similar issue even with the official app on the Ventura/Monterey/Big Sur OS).
You can try to take a look at your security & privacy in general tap on the yellow locker and input your password, then click on settings and put it on "open it anyway".
The other thing you can do is to use this command via terminal to remove the quarantine to the the extended attributes of the app.
Open the terminal then copy and paste this: xattr -d com.apple.quarantine file_path
then drag and drop the app icon to find the path of it and hit enter and it should work ( if you want to avoid issue copy the app on your desktop and then drag it on the terminal, if it work you can copy that again wherever it was before).
I will not give you the sudo command since that it can be dangerous, I hope with this that it will work I rarely used it but it worked.
P.S. Another thing you could do is making your own Mac version, you should download the latest rpgm engine and put inside the Resources folder the www folder, renamed in app.nw, I can give you the link to download it if nothing else work.