Help! Media players crashing

I need help, please.

Since two weeks, new movie files that I have downloaded, don’t play, they open the player (WMA, PowerDVD, BSPlayer...) and it crashes instantly, then asking if i want to send an error report. I’ve noticed that it happens also with movies that I already had, and seen on my PC. Some play, some don’t.

I have not installed anything as far as I’m aware, but I wondered if there’s a new codec I need...

Desperate to get this sorted, I hope that someone can help

Thanks,

Adan