Missing project handle

A project handle suddenly went missing. Only the project title remains, but the little round checkbox is greyed out. Command Outline > Expand Items returns nothing. I cannot reproduce what I did - nothing special in any case.
Have I lost all my data?
TaskPaper 3.8.10, macOS Mojave 10.14.6

By trying anything, I just found out Outline > Go home expands all project items. (Is this command not redundant with Outline > Expand all completely?)
I will now read the manual :slight_smile: