can not right click on mac

Good morning!

I am using AFNI on my MacBook. When I right click on the brain images, I see a menu appear briefly and then disappear, and so I cannot select things on this menu. What would be the reason and how to fix it? I updated AFNI but the problem is still there.

Thank you for your help,
Duong

Check your mouse preferences in both the mouse settings for the OS and in the XQuartz settings. Also it’s much easier if you are using a mouse rather than a trackpad.