Frescobaldi: 3.2
Extension API: 0.9.0
Python: 3.6.9
Git branch: master
on commit: a46047a0
python-ly: 0.9.6
Qt: 5.9.5
PyQt: 5.10.1
sip: 4.19.7
qpageview: 0.5.1
poppler: 0.57.0
python-poppler-qt: 0.24.2
OS: Linux-5.3.0-62-generic-x86_64-with-Ubuntu-18.04-bionic

Traceback (most recent call last):
File "/home/simon/frescobaldi/frescobaldi_app/historymanager.py", line 
68, in setCurrentDocument
self._documents.remove(doc)
ValueError: list.remove(x): x not in list

Optionally describe below what you were doing:

I clicked on a link in a Lily-produced pdf, which triggered opening of 
another source file to which the link pointed. The source file opened 
halfways: I see the code, but the tabs look like before (i.e. no tab for 
the newly opened file).