I'm fairly new to illustrator. Do I have some save settings wrong? I have several (not all) quicklook thumbnails showing up like this.
I'm running Illustrator 2025 on a MacBook Max M3 with Sonoma. I get the same bad quicklook previews on my Late 2013 MacBook Pro, running Big Sur too, so it doesn't seem to be an issue with the MacBook Max or Sonoma.