Here is your file edited. This is what I did to make it work:
1 - removed the "not occupied" condition and set it to an else event. This means anytime the previous event fails, the else triggers.
2 - As a bonus, I combined all 4 of your set worker animation events into a single event.
Hope that gets you what you need and good luck with your project.
p.s. I didn't really look too hard into why the "not occupied" event failed.