The ca-XV language (Valencian) is not supported by standard glibc.
Moving to a smaller monitor
If you have the misfortune to need to replace a monitor with a smaller one, you can find that LO is unusable because it opens with the menus and window controls above the screen and cannot be dragged down. If this happens to you, find registrymodifications.xcu in ~/.config/libreoffice/ (for 6.3 this is in 4/user) and rename it (with LO killed or otherwise closed.
You can then open it as normal, but all your local customizations will have gone. I suppose that if you have a lot of those you could (after verifying that LO now works and closing it) take a backup copy of the new one, and then attempt to edit the customizations into the new one.