Seadrive keeps leaving one unsynchronised file in each folder

Seadrive 3.0.19 keeps leaving one unsynchronised (not uploaded) file in each folder. It is alwyas only one sinlge file but in every folder. If there is a folder in folder with files there will also one unsynchronised file. Filenames are simle like 12.png of main.pdf. All other files of same kind and similar names and sizes synchronised.
What could be a reason?

Thanks,

Mitya

You can open and check “file sync error” dialog. Some sync errors related to these files may be logged there. The dialog can be opened from the right-click menu of the SeaDrive logo in system notification area.

You may also check the logs file (seadrive.log) for sync errors. You can also open the log folder from the right-click menu of the SeaDrive logo in system notification area.