I used to see line numbers pretty often with my Pico8 games, but recently I almost always get "Line 0 (Tab 0)" errors.
I'm running Version 11.

Is there a common reason for this? A way to get around it?

Yeah, this happens really often. And even: "Line o.4353343 (Tab 0)"

I get this. Often when running code that is in an objects methods.