Hello guys,
Thank you both for your replies. I still hope that my data is still somewhere around, but I agree that it smells quite bad 
I do have “many” backups, but the oldests are in the same state
I’ve just tried to export one of the libraries containing unreadable file, but it can’t find the block
Unfortunately, the seafile_recovery tool (Tutorial: recover your data even if your database is corrupted) is quite old and is using deprecated packages 
I’ll try to install an older version of golang in a test server 
EDIT1: I finally made the seafile_recovery tool working. Unfortunately, it still not able to reach the data I want BUT thanks to the error message :
“2025/06/28 20:01:07 open /seafile/storage/blocks/4fc822a3-42e4-4dbf-8a0d-f122816e572b/d5/234092dbfc9f84bc41baac5d8f54f68916a4df: no such file or directory”
i was able to retrieve this specific block in an older backup. I’m trying to restore it rn