For some mkv files, I can't get subtitles to load in MPC-HC, but they load fine in VLC. But subtitles in most mkv files display fine. I'm not sure what the difference is between the files that work in MPC-HC and the ones that don't.

The subtitles don't work for these files when "Play => Subtitles => Enable" is checked (I have subtitles enabled by default).

They also don't work when I select the subtitles track from "Play => Filters => [File Path] => S: [English]."

And they don't work when I select the "S: English" track by right clicking the Haali media splitter icon in the system tray.

(I think for the mkv files that don't work, the "S: English" track is not selected when the files are opened, but the "S: English track" is selected for files that do work.)

After a lot of searching, I am at my wits end, and I'd appreciate any help. I have installed several codecs and filters that I don't really understand, and I think a configuration issue may be causing the problem. I have installed:

AC3 filter
CoreAVC
Haali media splitter
VobSub