Anonymous - 2015-10-15

Hi, can you pls help me with videos in mp4?
I installed K-Lite codec pack and everything was OK. Today I switched on Subtitle Workshop, opened the .mp4 file, which I was translating yesterday and today I was not able to play that video in Subtitle Workshop Preview. I tried to reinstall K-lite codec pack and the problem is still same...
Is there anything what I can change in settings of LAV or K-lite?