Final Cut Pro - The share operation “Export File: “*File name*”” has failed

To whom it may concern,

I am a wedding filmmaker and use Final Cut Pro to edit all my videos. Over the last few months, I've been running into this issue where I go to export the wedding highlight video and it comes back with an error message saying "The share operation “Export File: “*File name*”” has failed." It goes on to say specific details of where it failed (See screenshot). In times past, I've been able to go to the specific frame where it says it had an error and I can usually figure out what went wrong. Often times it seemed like some effect wasn't fully loading and I'd have to refresh somehow.

This worked for a while, but more recently, I've been doing all the troubleshooting things that I have done in the past, restarting my computer/final cut, going to the exact frame, deleting and reapplying effects, switching 'Views' from Better Quality to Better Performance (it seems to refresh the timeline or something and it's worked before), etc. but nothing is working. I can export proxies of the same video as well as full quality (4K) ceremony and toast videos that are much longer, but have fewer effects applied no problem. It's always the full quality montage/highlight videos that I have issues with.

It's gotten to the point where I just sit there for hours trying over and over again to get it to export and usually it eventually works, but it's extremely frustrating.

If anyone could help me out with this, it would be greatly appreciated!