Unmarshal: invalid character 'ÿ' looking for beginning of value

Impossible to use any restic command other than restic version…
I get this:
Fatal: Unmarshal: invalid character ‘ÿ’ looking for beginning of value

I have already check the key, but it seems good. A json format with date, usename, hostname, salt and data etc etc…

Our restic version:
restic 0.12.1 compiled with go1.16.6 on linux/amd64

Please include the complete command you run, and all of its output, when you get this error (you can simply edit your initial post to add it).

I would also encourage you to try the latest restic version, in case it has any bearing on things (yours is somewhat old). It’s just a single binary that you can download here: Releases · restic/restic · GitHub

I cannot find how to edit the post, so i’ll do this here.

This is the error with the latest restic binary:

I will repeat myself, but ALL command that open repository i’ll get this error.

I can add that the message appear after entering password and whether it be with the good and a bad password is the same.

Can you please run xxd on the key file (name starting with 9a4d32) and paste the fist few lines?

I suspect that something inserted a unicode byte order mark (which is invisible when inspected via cat) at the beginning of the file…