[popcorn]

I've determined what I think to be a workaround.

DisplayLink launches a process called "CrashRestartHelper" when it is run.

Ending this process in Activity Monitor prevents the popups from occurring on my machine. I'd love somebody else with the problem to validate.

--

Also, this thread seems to confuse two similar issues. For the issue where you get a popup saying "DisplayLink Manager is already running." that is the Elgato issue, it can be corrected by going to the Elgato Camera Hub software, hold down the CMD key while opening the Preferences page to show the hidden setting "Ensure DisplayLink Manager it running" and then uncheck that box.