X: Fonts showing as squares when running programs on remote server

[ATC]

Running X programs normally works OK but when trying to run a program from a remote X server, the fonts show as rectangular squares, "waffles" or other weird symbols instead of the text.

[ATC]

Verify that the X Font Server is running on the X client. If it appears to start but does not actually run, try running it manually ("xfs") and observe the error messages.

The most common problem is missing fonts, try running "fc-cache --list" to verify that the installed fonts match the current configuration.