I can't load subtitles with mp4

I use Windows Media Player 12 and K-Lite Codec Mega.
I can use them very well except mp4 files.
When I play mp4 files, the subtitles don't running.
What is wrong?

p.s. I don't want to use any different player. I want to use WMP 12 only.

CTT > Media Foundation > Disable for .mp4
If you are using Windows 10, then do the same for .mkv.

The preferred decoders are already configured correctly by default by the installer, since those tweaks do not have any bad side effect.

I can watch a video well now.
Thank you for you advice!

I have some question to Admin
- If I disable Media Foundation in MS Codec tweaks, do I need to disable format in Media Foundation settings?
- Should I disable Media Foundation. Is something bad if I do it?

Thank you for your wonderful codec pack

It is recommended to disable Media Foundation only for specific formats.

Click on the Help button in the Codec Tweak Tool to get more information about possible side-effects.