Decryption failes after reinstalling Windows


i am using owncloud with master key encryption. After reinstalling windows on my pc i get an error while fetching encrypted files:

Server hat “500 Internal Server Error” auf “GET https://xxxxxx/owncloud/remote.php/dav/files/Volrath/links.txt” geantwortet (Can not decrypt this file, probably this is a shared file. Please ask the file owner to reshare the file with you.)

I am logged in as the owner of the file who is also admin. So i don’t understand how the owner can share files with himself?

Maybe there is a folder on the clientside where i can put the master?


Maybe it’s because of https? Because currently i have no valid certification?

I am facing still this problems even after i renewed the SSL certification