Impossible to load any office document

Hello,
I have installed nextcxloud on an openmediavault 6 NAS system. This runs through a swag docker. I have a collabora container runing, but when I try to load any office document, I get a screen like the one attached. It seems that there is no connection with the collabora database runing on the system.
Thanks,
Best regards,
Harold

Please follow this guide Nextcloud Collabora integration - Wiki - Nextcloud community