Comment 7 for bug 374320

confirmed, and removing btmp in /var/log/ means the error changes to:

Error stating file '/var/log/btmp': No such file or directory

On top of this, going to help file:

To stop monitoring a specific log, uncheck the View ▸ Monitor option.
Check this option again to turn monitoring back on.

There is no 'monitor' option in the view menu.

Going upstream to find out what's going on.