Unable to Backup with acronis

Hi, im trying to to backup to the public share of my cloud home.
Im using the regular Acronis True Image 2018 version, not the WD version.

Whhen i try to start the backup im immediately getting an error, “backup cant be opened”.

I guess its because of some access right. I tried to enter login credentials, -> user "guest, password “guest” but they are not accepted.

It doesnt matter if i map the drive by ip or name. Always the same error.

Any ideas? Am i missing something?

Ditto. Did you ever get it sorted?