How to fix Nextcloud Office error message

Error: no_fontconfig

What can I do to stop having this error message?

You can either uninstall it or address the missing requirement.

See:

But without more information (such as that requested by the support template) about how you have Nextcloud installed, it’s impossible to be of further help. One approach would be to run Nextcloud in a container, with all of the requirements. There are other approaches.