Illustrator Startup "Operation cannot complete" Error

Just tried the solutions suggested by Adobe Staff in Bill's link, as well as deleting my OOBE folder, deleting any other Illustrator prefs I could find, and finally flat-out wiping Adobe CC from my machine and then reinstalling.

After several hours, I still have that SExi error dialog come up when I start Illustrator. Doesn't stop the app from running, but I'd kinda like to understand how to make that dialog go away. Oh, and I get to redo my prefs. Thanks Adobe!

Windows 10 Home, v10.0.17763, Illustrator CC v2015.3.1

Edit - Because Why Not, I took travisryan's advice in this thread​. I still had Illustrator installed at the moment (this would be after the second reinstall), so I figured why not, three's the charm, so I uninstalled it via the CC app, then blew away the two folders that remained inside C:\Program Files\Adobe\Adobe Illustrator CC 2015.3\Plug-ins. Dragged them to the trash, emptied the trash. Reinstalled Illustrator CC via the CC app. Opened it via the CC app (as opposed to double-clicking on the Illustrator app inside Windows Explorer). And.... it worked. No SExi dialog.

Closed Illustrator, reopened it the same way. Still worked. No dialog.

Opened Illustrator via double-clicking in Windows Explorer, while the CC App was still open. Still worked. No dialog.

Opened Illustrator via double-clicking in Windows Explorer while the CC App was closed. Still worked. No dialog.

(You'll note the inanity of doing all these things over and over again, just on the off chance that something might change. Yes, it is. But if I hadn't been open to trying Inane Things I've Already Tried, then I would have just given up after trying two full reinstalls of Illustrator. So now we perpetuate the idea that even though things don't work in Illustrator (including Adobe's own advice and their CC Cleaner App), then one just has to keep trying Black Magic because sometimes it works. That's some really good software there, Adobe.)