When LibreOffice was first released I instantly installed it (via pacman) on Arch Linux. Having read lots about the grand work the project was doing to finally bring the project upto date since forking Open Office I was interested to see what they had achieved. I was quite impressed.
I don't do a lot of document based work on my Arch laptop (and there have been a number of updates since I last used it) but I went to type up a letter for the wife tonight and fired up LibreOffice and found the UI was rendering in what appeared to be Russian (which I do not read or write).
After a bit of digging about it appeared I made a fatal error in installing the libreoffice-uk language pack. Turns out that is the Ukrainian language pack ... oops!
It turns out that I am not alone in making this assumption and if you happen to hit this issue and you actually need English and not Ukrainian then install the libreoffice-en-GB language pack and all will be well (and readable) again.