I updated to Version 5.0.4.2. LibreOffice on Debian 8.2. The spell check function does not work. The auto-spellcheck does not work, either. I’ve had this version for about a week or so. The spellcheck worked up until yesterday (Jan. 7, 2016).
How do I fix the spell check in Version: 5.0.4.2 Build ID: 00m0(Build:2) Locale: en-US (en_US.UTF-8)
If you did sudo apt-get update/upgrade, then the issue occurred - I’d recommend filing a bug with Debian.
https://www.debian.org/Bugs/Reporting