iMovie freezes after working on a project after few minutes

There are 2 other things you can try that are very easy and quick.

1. Sometimes there can be a problem with the project or even one clip you are working on. Close the project and start another new "test" one . . . just import some different video files, dump them onto the timeline and add a few transitions and effects. If your problems don't return you will know that there is something dodgy about the original project.

1. This may sound very strange but has sometimes caused untold trouble. There could be something amiss with your User account. To test this, create a new user account for yourself and use iMovie in that.

There are a number of things that an cause an app to freeze. Possibly you have insufficient space for iMovie to function efficiently. Check your free space and make sure that you have at least 20GB.

When you refer to the "engineers" do you mean the techs at Apple Support? They don't always solve the issue but I don't recall any complaints on this forum of appalling "treatment and follow-up". Most people report that the techs were great at addressing and solving their problem. Since your experience was different I would suggest that it is the exception rather than the rule.

I don't know what the engineers told you to do, but here are a few things that you can try:

Deleting Preferences

Try opening iMovie while holding down the Option and Command keys and selecting to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects.

New Project

Another

thing you can try is to copy your media into a newly created project and see if that cures the problem. To do that, do an Edit/Select All, Edit/Copy, of the media in your project and then Edit/Paste it into the newly created project.

Safe Mode

You could also try booting up in Safe Mode (see Finder menu for instructions) and, after everything loads, immediately shut down and reboot in normal mode. Then see if iMovie works properly.

Resetting the System Management Controller

Try resetting the System Management Controller:

https://support.apple.com/en-us/HT201295

 Resetting the NVRAM or PRAM

Try resetting the NVRAM or PRAM, although this issue would be fairly rare:

https://support.apple.com/en-us/HT204063

-- Rich

I am thinking that you might have faulty RAM or a defective graphics card, or other hardware issue. To find out, run the Apple Diagnostics program on your Mac. If your computer is pre-early 2013 the program is called Hardware Diagnostics.

This link will explain how to use it:

https://support.apple.com/en-us/HT202731

-- Rich

Yes I have a similar problem that I did NOT have with iMovie 9 on and 2011 Macbook Pro. I just bought a more powerful 2020 Macbook Pro with iMovie 10 and it is almost unusable. After working on a project for 5-10 minutes, I move a media or audio clip around the slightest bit, or even add in an simple sound effect in a project, I get the spinning ball and have to wait. What I am typically doing is doing voice-overs on a powerpoint, or editing zoom meeting movies. It doesn't matter how big the file project is, but what does seem to be a factor is it starts after working on the project for over 5-10 minutes. The only thing that I can do is quit iMovie, and open it up again. I have heard it has something to do with background tasks, so if anyone knows a work around to stop these, I'd appreciate it. I am for the most part computer illiterate, please use simple language.

I know! I have had to make online lectures for teaching since April, and had been recommending iMovie to the other instructors as a great way to do their presentations, but now I tell them I am sorry I just bought this new MacBook and am looking into Camtasia since iMovie is almost completely UNUSABLE. I have to think Apple is floating on their rep and don't really care for what they must consider these niche problems. I really shouldn't try all these work-arounds to fix a bug in their system.

Have you tried a hardware check?

— Rich

Hi, have they figured anything out about this for you yet?