Maybe you installed a new application (or uninstalled or updated a program) around that time?
How do you load a DVD (rightclick > Open DVD ... etc)?
Apparently (looking at the picture) you're not using latest BS.Player-version.
Maybe update first.
These properties will only be functional (and not be greyed out) when that codec or filter is actually used in decoding a specific movie.
To find out what codecs/filters are used for a specific media file, please load it and then
(rightclick>) Options > Filters > Advanced
Clicking on the [+]-
signs in front of the codecs/filters will reveal further info and access!