quicklookd Failed to generate image with request <private>

[coso]

Since a couple weeks ago my 2015 13" MacBook Pro would randomly start to stutter (choppy scrolling, lags when typing, fans at full speed etc.). It basically becomes unusable.

I noticed that when happens in the console I have dozens of these messages in a row:

quicklookd Failed to generate image with request <private>

When it happens I see that the Windowserver process can take up about 1GB of ram and eat most of the CPU time.

I already tried resetting SMC / NVRAM, killing pending Finder searches, emptying quick look cache, clearing and restarting spotlight, and also creating a brand new account on the Mac, it still happens. I already reinstalled Mojave 10.14.6. I did a clean install a couple months ago when Apple changed my battery and a temperature probe under warranty. It ran fine back then.

I have no crappy software installed and no virus/malware.

I can't understand what it could be..

 

[coso]

So ok I discovered it was Unclutter. Once that was closed the errors went away. The latest macOS update must have done something because it was fine before. Now I'll just wait to pinpoint what else freezed my system, I remember trying to shut declutter off earlier with to no avail.