I have this issue - AI files not previewing in Quick Look on Catalina. When viewing an AI file in a window pane or hitting space bar, all that shows is the AI icon (every other file type previews OK). Being forced to open an Illustrator file just to see what it looks like is beyond inconvenient. If I right click and select ‘open in Preview’ I can see the file content but as I say, that’s far from ideal, it’s Quick Look I need for my workflow. I’ve had extensive discussions with Adobe techs who are sure it’s a MacOS issue and yesterday spent 7hrs chewing the fat on this with 5 different Apple advisors. The most puzzling thing to me is, I can’t find on any Adobe or Apple forum another sole with the same issue. I do know I’m not alone though as 2 of my work colleagues have the same issue and are looking to me to resolve it but, as I say, there’s that bloody wall! My iMac with this issue is 2013 running Catalina (updates not compatible) the 2 other designers are working on 2017 iMac (Big Sur) and 2020 iMac (Big Sur). I also have a 2011 iMac running High Sierra - AI files on that preview just fine. To save anyone who feels they can contribute wasting their time, I’ll confirm trouble shooting already done (to no avail): • All AI files are saved with PDF compatibility. • AI preferences file deleted from library. • Reinstalled Adobe Illustrator (3 times) • Through Terminal - reset ‘qlmanage -r cache’ • Through Terminal - Cd ~/desktop - find . -name '.DS_Store -type f -delete • Reinstalled MacOS Catalina Advice for the next step is to reinstall older OS like High Sierra or Mojave, if AI preview returns it will confirm an issue with Catalina. I may try that but would be massively disruptive as I have 1TB data on this iMac and links to several cloud based resources. Also, downgrading doesn’t solve the issue of why it’s happening to me and 2 others using Big Sur with no sign of it being an issue to anyone else! Any ideas gratefully received!