"MigratorUIAgent cannot be opened because of a problem"

Hi Aaronite,

Thanks for using Apple Support Communities! We see you're getting a message popping up sometimes which is a mystery as to why. We're happy to do all we can to help.

The best steps to isolate why this "MigratorUIAgent cannot be opened because of a problem" message is appearing is some basic troubleshooting. Let's get started with that first.

Have you restarted your iMac since noticing this pop-up? If not, go ahead and do that, as a restart can resolve unexpected issues.

Log out, sleep, restart, and shut down

If it still happens, try starting up in safe mode.

How to use safe mode on your Mac

It may take longer to finish the start up, as safe mode does some system checks, and can sometimes resolve issues. You'll also see some differences in the display. This is expected with safe mode, and when you restart normally, they'll be gone. Testing for the pop-up may be challenging, since it doesn't always happen. After getting to your Desktop, give it a minute or so, then restart normally.

Another test is to see if the pop-up occurs when using another user profile. If you don't already have another user, here's how to make one.

Set up users, guests, and groups

If none of these steps are successful, and the pop-up continues, let us know and we can provide some additional troubleshooting. Please also verify which macOS you're using, from the Apple  Menu > About This Mac. However, do not include a screenshot, as that would contain personal information.

Thank you!