Short summary in case you wonder what happened to forum.
- phpBB was updated to v3.2.2
- This completely broke the we_universal theme (that was already broken with 3.2.1 update)
- After ~2.5 hours of trying to fix it, I went with black-silver theme, substituting banner picture with lulzbot banner. The theme is here: https://www.phpbb.com/customise/db/style/black_silver/ v1.1.6