I'm unable open any DMG file after upgrade to macOS Catalina. I keep on getting the following message "The following disk images couldn't be opened" Reason "no mountable file systems". Diskutil for some reason will not mount the image.
Any help will be really appreciated.
Works fine on a Catalina system I recently created. Try a safe boot and reboot again in normal mode. Any better?
Try a second account -- any better?
Have you done anything out-of-the-ordinary or special to your Catalina system to change the default setup?
Try posting an etrecheck report.
Good luck...
I downloaded Camtasia (a video recording app from TechSmith) both its primary app dmg and its special update dmg's are popping up with the dialog below. There is no fix. Holding Ctrl / Going to Settings Security ... nothing worked. I can't open their DMGs.
Unable to open any DMG file after upgrade to macOS Catalina
