Microsoft OneDrive has a function called “Ransomware Protection”. This function checks all files in your cloud and forces you to regard files which where encrypted by 3rd party tools like Cryptomator.
When you dismiss checking your (encrypted) files, they will be removed after 30 days!
I have contacted Microsoft support. They told me, that this is a known issue which can’t be turned off.
They also told me that there was an UserVoice feedback survey, which suggests to turn the RansomWare Protection to an optional feature.
I think it woud be very helpful to support this suggestion. You can find the survey here: Add the ability to disable ransomware recovery
Microsoft will regard this suggestion when >500 voices are reached. I think this will be a good think and i would kindly ask to support this.
It would also be very helpful if Cryptomator officially supports this survey (i.e. facebook, Twitter). I know that is something like a “political issue”. But i also think that this is a very high risk - if this makes school, every infrastructure for self-driven encryption tools is destroyed!
Joerg Kalisch (Germany)