Which ROM for 9195 Germany DBT?

[LovingMy9195]

I have a s4 mini 9195 LTE in pretty pristine condition which had been smoothly running KitKat 4.4.2. I updated the OS from the phone's software menu and afterward restarted the phone (perhaps too soon after upgrade?) and *poof* all I could get was the Samsung Galaxy boot graphic, recovery menu and download menu :'-(

The phone is an unbranded DBT. In the stock Recovery menu, I can see I had this ROM I9195XXUCOE4 as well as the message "unable to mount /data"

I don't know what my system was updated to (I think 5 - Lollipop? The upgrade was 89MB).

My question is:
Does it matter which I9195 stock ROM I flash? I have not found a I9195XXUCOE4 to download (404, "file deleted", fakes, paywalls, etc.) but rather other ROMs ending in CNH etc. Doesn't Android 5 Lollipop have something "FSP?" to prevent updating older OSs such as 4.4.2? Nor have I been able to find a NEWER Lollipop ROM to install.

Any ideas?

 

[LovingMy9195]

Key information: I am a complete flash-noob.

My Plan B is to install TWRP and try to use it to change the format from ext4 to FAT and back to ext4 to alleviate the failure to mount /data. This is an idea from Youtube and the gist seems to be to force e2fsck to run. Maybe? I am not sure this will even work because my phone is encrypted (slow clapping myself here now). I think I'll have to root the device to get it to work with the encrypted /data and so I downloaded Magisk. The goal here is that I'd love to pull some data from the phone but I am aware that this is probably utopian.