Ah, ok, thx, then the wiki is just a litle bit confusing.
Cause there it looks like different things, "invalid or missing key" includes the sub-point trial key description, but "cannot contact key-server" just descripe:
"If your server is unable to contact our key server to validate your license, you will not be able to start the array. The server will attempt to validate upon first boot with a timeout of 30 sec. If it can't validate upon first boot, then the array won't start, but each time you navigate or refresh the webGui it will attempt validation again (with a very short timeout). Once validated, it won't phone-home for validation again unless rebooted."
https://wiki.unraid.net/UnRAID_6/Storage_Management#Cannot_contact_key-server
Thats why i asked.