File not Found for encrypted files on S3

I have Amazon S3 as external storage and encryption enabled. This was working fine for months. Now I'm getting 404 on all files. If I disable encryption for the external storage then I can download the files, but given that they're encrypted I can't open them.

How is it that having encryption enabled results in a 404? And how can I fix this?

Please fill out the issue template shown when creating a new thread in the oC server category. Currently even the basic infos are missing.

Closing due to the lack of feedback / info.