Had a bit of a scare yesterday. I'd created a video using 13.66 and when I played the video in VLC, the audio came out normally but the video would mostly freeze in a random frame. Every now and then a new frame would appear, but not very often. Even the most basic video, with just one mp4 and no editing at all would behave the same. Strangely, I thought I had already created a video last week with this same version (though I could be mistaken) and it had no problems at all. Luckily upgrading to 13.67 fixed it. Phew.... I am very relieved.
Does the problem ring a bell to anyone ?