If I unmount coolwsd.xml I get the error Failed to establish socket connection or socket connection closed unexpectedly. The reverse proxy might be misconfigured, please contact the administrator. For more info on proxy configuration please checkout https://sdk.collaboraonline.com/docs/installation/Proxy_settings.html

If I mount it, I get the error Unauthorized WOPI host. Please try again later and report to your administrator if the issue persists.

In my Nextcloud, under office settings, I set 0.0.0.0/0, “Allow list for WOPI requests”.

I have enabled and set Nextcloud (Collabora), selected “Use your own server”, put my Collabora Tailscale domain, and the page shows green.

I have these set in a .env file for Collabora

DONT_GEN_SSL_CERT=YES  
extra_params=--o:ssl.enable=false --o:ssl.termination=true --o:net.post_allow.host[0]=.*  
aliasgroup1=http://.*  

My Collabora container does not have Bash, nor sh, and I’m not even to run any commands like cat or console into the container to help debugging.