Apologies if this has been covered elsewhere, but my searches haven’t turned up anything.

I’m experiencing really strange behavior in outline mode—when I click on the text within a specific level of the outline, that text completely vanishes. If I click on another level, the missing text comes back, but text I clicked on this time disappears. This makes it impossible to edit text.

The problem started when I copy-pasted some text from another notebook. This text was highlighted in the other notebook, if that provides any clue. Notebook crashed the first time I tried to copy-paste this text.

Can anyone help? Thanks.

Mack