Your comments

No problem, I will check later when you share one file

The database scan script runs but doesn't return control. A new scheduled execution must be triggered for a scan to run again. Otherwise, there's no way to start a manual scan, as the button indicates that a scan is in progress while the ongoing scan never completes.

Mince ! I have no clue :) let's share several of those "récalcitrants" files for analysis....

The database scan script runs but doesn't return control. 

A new scheduled execution must be triggered for a scan to run again. Otherwise, there's no way to start a manual scan, as the button remains inactive while the ongoing scan never completes.

I have met the same kind of issue for several of my files. The reasons identified so far :

- filenames with "accents", such as é, à, è, etc. were not well scanned although other users have no issue with accents... Then, I have removed all accents within my filenames.

- RAR5 files, which are not readable by ubooquity, but then that should be not working both on ubooquity v2 and v3... 

Then there are many possible reasons for such issue

File CANNOTREAD.cbr --->

CANNOTREAD.cbr: RAR archive data, v5

To complete they were opening fine with Ubooquity v2 while I am facing that issue with v3.1.0

Maybe you shall share several comics which are not scanned 

and/or give details about them