Unable to connect to the Collabora Online server, Error: no_fontconfig

I downloaded and activated the Collabora Online - Built-in CODE Server version 25.4.702 and Nextcloud version 9.0.2 apps. Opening docx files resulted in an endless loop to load the file.

In the administrator settings for Nextcloud Office, I see this message (first line translated from German to English):

Unable to connect to the Collabora Online server.

Failed to connect to the remote server: Client error: `GET https://mydomain.net/extra-apps/richdocumentscode/proxy.php?req=/hosting/discovery` resulted in a `400 Bad Request` response:

Socket proxy error

Error: no_fontconfig

It seems that fontconfig may not be installed. However, I don’t know how to check this or how to install fontconfig.

For the sake of completeness, I would like to mention that the following message appears during the automatic check at the beginning of the administrator settings (translated from German to English): The PHP module “imagick” is not activated, but the theming app is. In order for favicon generation to work correctly, you must install and activate this module.

The Basics

  • Nextcloud Server version (e.g., 29.x.x):

  • Operating system and version (e.g., Ubuntu 24.04):

    • Linux 4.19.0-18-amd64 x86_64
  • PHP version (e.g, 8.3):

    • 8.3.23

    Is this the first time you’ve seen this error? (Yes / No):

    • Yes

Please read the app store entry or other resources regarding system requirements:

Thank you very much for the hint regarding the system requirements. I have read it and that is why I think that fontconfig is not installed. However, I do not know how to install it. It is not available as an app that could be activated (and thus installed).

Is there an guide for installing fontconfig?

It would be a package provided by your OS distribution.