You may have a problem with the location of your received files. Looking at your screenshot of your MSGDataManager it states: C:\EUMETCast\received. Mine is C:\EUMETCast\received\bas.
You should try clicking the box prüfen to check if your files are in the right place, if this finds no files then try adding \bas and check again
Of course it depends on your individual installation but if you used the standard install offered by the Tellicast 2.14.4 that should work.
You can also check on your C: drive to see if you have 2 folders installed: EUMETCast and EUMETSAT , check the first folder which should have 3 subfolders: logs/received/tmp
My received folder has 2 subfolders bas and has-1 because I take both the basic and the high volume service. I am hoping you will at least have bas.
The bas folder on a standard install has a lot of subfolders! Just to get started you will need to ensure that MSGDataManager checks this bas folder as described above.
Hope this helps you