Command-Spacebar-Click zoom stopped working

[Rightbrainforhire Heidi]

It works fine in Photoshop, but only works in Illustrator if I don't show rulers (Command R) or adjust my artboards from the toolbar. If I do either of those things, the panel goes black for two seconds and the zoom shortcut no longer works. I currently use 2021 because I cannot upgrade to 2022  (CutStudio Plugin for cutting vinyl won't work in the new update).  In fact, the whole programme is way less responsive after I've added rulers or fussed with the artboards.

I use this shortcut a lot and would like to continue. 

[Rightbrainforhire Heidi · Accepted solution]

I may have solved this my own self. I went into the Preferences file (finder) and trashed all the preferences from every version of Illustrator I had installed). Seems to work. For now...