Failed to listen on Server port


I have set up on my nexcloud collaborator office server.
But it does not launch: “Could not establish connection to the Collabora Online server.”

I tried this:
Collabora integrated CODE server cannot start / not workin / not reachable [SOLVED] - :information_source: Support / :page_facing_up: Collabora - Nextcloud community

But I got an error message :
Logging at warning level to file: /tmp/coolwsd.vtYsohi6Xn/coolwsd.log
Failed to listen on Server port(s) (9983-9983). Exiting.

Do you know where it can come from?

thanks in advance