Zwift Not Loading on MacBook--"Forbidden" Window

Hello. Long time Zwifter. I generally use my MacBook Air to do so. Yesterday afternoon I could not get the program to load–shows this window when I click on the Z logo in the dock:

I’ve tried uninstalling and reinstalling twice with no success. I was able to get in with no problem on my iPhone and have used that the last two sessions. Any help is appreciated.

Thank you.