Problem suddenly started. Pinwheel and moved cursor

Hello,

A problem just developed with my Final Cut Pro where when I move a clip I and hit play I get the pinwheel for 10-60 seconds and then the cursor moves to the end of the project. This makes using Final Cut nearly impossible.

I have tried deleting preferences. I have un installed and re installed.

Final Cut version 10.4.6
OS: 10.13.6 High SierraMacbook Pro (Retina, 15-inch, Mid 2015)Processor 2.8 GHz Intel Core I7Memory 16Gb 1600 MHz DDR3Graphics Intel Iris Pro 1536 MB
Here's a video where you can see me make a new library and project and immediately have this problem:

You might try running EtreCheckPro on your system:

etrecheck.com/en/index.html

It would help to know the specs of your project as well as the format, codec and frame rate of the clips you are putting into the timeline.  It is also important to have enough free space on your internal hard drive drive to deal with the media and library you are creating there.  Typically 20% of your drive capacity should remain free.  I did notice at .33 sec into your video, a dialogue appeared as you dragged a clip onto the timeline which stated the video properties of the clip were not typical.  You ignored that and dragged the clip in anyway which set your project for 720p  (960x720 at 30fps).  Not sure what your clips really are.  May not be an issue, but this is also why knowing the format and codec of your clips is important.  The performance issue could be related to placing your media and library on your internal drive.  If you have a fast external drive (preferably SSD or better) you could try to place your media and cache on that to see if performance increases.  You are also trying to playback 3 layered streams of video, and it seems like you're seeing a resource deficiency.  Have you played clips like that in the past successfully without any lag or beachball?  If yes, that might tell us something.  You can also switch your viewer to "better performance" if it is set on "better quality" and see if that helps.  In your FCP preferences, make sure that Background rendering is turned off.  When you deleted your preferences this would cause it to be turned on at next launch, even if you previously did have it turned off.  Finally, there was a bug in FCP very similar to the effects you are seeing - beachball and then playhead jumping to end of the timeline, but I don't recall what version(s) of FCP that occurred on or exactly under what conditions.

"Have you played clips like that in the past successfully without any lag or beachball?" 

Yes.

Usually I would be able to work any kind of file/codec from internal or external drive, using that many clips and it wouldn't glitch. This is a recent development. I have about the same amount of open hard drive space as before this problem started.

I'm thinking....I just closed out google chrome and it didn't glitch out for the first time since this problem started. That might have something to do with it. Still, it's a change but maybe it's Google Chrome's change not FCPX? 

Thanks for all the tips! I'll see if this problem starts up again!

Well, Chrome is almost certainly what your problem is. This has been a known issue affecting FCP since 2020 or earlier. Just closing the browser is probably not enough to eliminate the problems it causes. You can learn more about it and find the complete uninstallation procedure here : chromeisbad.com