M1 build Access denied

[elbows]

See this thread:

Unity on Apple silicon and Big Sur: Known issues and workarounds

This page contains known issues and workarounds related to running Unity and games made in Unity on Apple silicon hardware and/or macOS Big Sur operating system. Note that native Apple silicon support for the player was added in Unity 2020.2.0a21. We plan to release an alpha version of the editor that runs on Apple silicon hardware natively in Q2 2021. Unity player issues Fixed issues Unity editor issues Known issue: macOS Big Sur beta 10 and later hangs on Apple silicon hardware when using…

So its probably either the Mono issue or the non-development build code signing issue.