I got the same issue.
I tried select-all and delete so there was no geometry left in the model at all, and it still did the same thing, so it wasn’t a geometry problem.
Next I tried select-all, copy, new file, paste and then the problem went away.
I’m guessing there was something weird like it hadn’t deleted a line properly, so it wasn’t available to the user, but it wasn’t fully gone either. Anyway - hoping this might work as a solution for others.