Final Cut Pro timeline is suddenly glitchy on playback, seems corrupted

Thanks for the reply and explanation, TerryB. I've been delayed with a busy week, and am finally getting back to tackling this ongoing issue.

To answer some of your questions:

1. As a test, I loaded and played a different FCP Library from last year. That project, let's call it Project B, had its library and its media on a separate SSD drive. Not from internal drive, not from Jellyfish server. THAT project still had playback issues! I cannot remember if the Jellyfish happened to be connected at the time I did that test. I didn't think that would be an issue.
2. You sound familiar with OWC/Lumaforge Jellyfish? The driver "Jellyfish Connect" was current and up to date when I started having these issues. This playback issue we've been discussing in this thread -- the ISSUE -- started, and so I looked into the health of my jellyfish server. It seemed to have one drive down, and that initiated a case call with OWC. They looked at the Jellyfish Connect driver and suggested that I uninstall and then reinstall the older driver. Which I did.
3. when you ask if I've done tests with no external devices connected, you mean running a Library and Media from my iMac's internal drive? I never store media on the iMac workstation, but I could try.
4. Has the boot drive always been encrypted? Here's where I really get exposed as a tech-newbie. I don't really know what that is or how to change it. Is that something I can change in Disk Utility? is this related to Ian R. Brown's comment about FileVault? And Tom Wolsky's comment about drives and encryption?

just as an FYI, I've been back and forth with OWC on the jellyfish issues I've been having with some drive statuses. I think those issues are separate, but a tech is going to log into my machine, shortly, to have a look.

I see that FileVault is switched on in my case, and I know it's not something I would have switched on purposely. I have no idea what it does. Are you sure it's safe to switch off, and I'm not going to have issues logging into things, or having keychain passwords disappear, etc? Thx.

Again, Tech-newbie here: if I understand what you're suggesting: I should run my iMac from an SSD with the OS installed on the SSD, and somehow, my machine won't be running from the OS that's currently on my iMac? That would be like having a fresh install on a computer that is just using my iMac as a monitor? And you suggest I install the FCP app on the SSD as well, and then run a FCP timeline from that SSD. Do you think I can have the OS and the Library and Media for the FCP test all on the same SSD drive?

When you say:

no migration, not sure what that means?

no Jellyfish, got it, I'll make sure it's disconnected

no disk encryption, you mean make sure the SSD is not ecrypted? If it is encrypted, do I have to re-format the SSD and start from scratch?

thanks,

Mathew

thanks for all the suggestions, I will do this testing. At the moment, my jellyfish sever is being scrubbed and analyzed, so I cannot do much with this work station for now. I hope to continue on the weekend or Monday, and I'll surely report back.

Thanks for the suggestions and for doubling back on the Etrecheck to ask about Zerotier.

I have no idea when or why I installed that App. I'm not sure if it's a background app while I'm editing.

I can get rid of it.

I am about to uninstall and re-install FCP with the various tips from you and Luis. Thanks again for the follow up.

Thanks, wow you guys really know how these machines work, haha! Yes, the Zerotier files are visible on my system, with that systems file parameter checked. So I'm guessing that getting rid of it is not so straightforward. There are a bunch of Reddit threads on trying different things to do it, and I wonder if I need simple instructions like the ones laid out in Chromeisbad.com to get rid of Chrome...?

Not as simple as dragging FCP to the trash and emptying the trash, and getting rid of render files, etc.

thanks. I think Luis Sequeira1 advised to "never install any antivirus or cleaners" in order to keep the Mac running clean. Would App Cleaner fall into that category, and is there some debate on their utility or pros/cons?

thanks.

okay, thanks for chiming in.

that would explain why my new install of FCP on a new install of the OS, somehow "remembered" my keyboard shortcuts that I had made.

Some of the files I migrated from TimeMachine must have brought over some preferences or something from the old original install of FCP, and those must have been lingering in these hidden files/folders like Preferences and application support.

I had only dragged FCP to the trash. Then ran TimeMachine backup, then did my reinstallation routine.

Hopefully my glitch issue does not return as well. If that happens, I'll migrate nothing over on another reinstall.

just did a quick search, and this site checks for adware/malware? Is that your hunch, that such things could be causing my issues? Thanks,

thanks for chiming in! Even with "crazy" in your handle, I'll believe you. Thx.

hmmm. wow, who knew? not me! Thanks for the tip and the link.

I'll investigate. Many thanks for taking time to review the report, that's very helpful of you.