Sage 9.0 installs, but OS says app is damaged


Tried to install Sage, three times using “brew cask install sage,” with the same result each time:

“SageMath-9.0 is damaged and can’t be opened. You should move it to the Trash.”

Any suggestions are welcome. Thanks.

Update: Having the same issue when using the dmg from MIT. Obviously this is not a Homebrew problem. Thanks again.