I think we have a misunderstanding
1.) Cura tells me "unable to slice"
2.) I move the model, and ctrl+Z to move it back to where it was, and click "slice" button again
3.) Cura slices without the error
Or
1.) Cura tells me "unable to slice"
2.) I pick a random variable, let's say "wall line count", i change it from 3 to 2 and back to 3 again, and click the "slice" button again
3.) Cura slices without the error
The slice button becomes greyed out, so I change the variable (again, ANY of them, doesn't matter) or move the model so it becomes clickable again
I wish I could tell you which error got missed, but the only thing I get is "unable to slice"
I uploaded the .log files a few minutes after it happened
Will do a screen record next time...