I have a yellow line in both the video and soundtrack tracks. The line appearaed yesterday, I believe after I added some black video as the first clip in my project, but not sure. I don't remember the yellow line prior to that but have now deleted the black video yet yellow line persists. I have rendered several times prior to and after the yellow line appeared. Now there is a yellow line in the soundstrack track below the video track. I have read Mr. Gissettis' replies at moviepix.com that it may have to do with the settings. If so show do I fix this. As I said there was no yellow line prior to yesterday and I have been editing this project for over a month
Lots of possibilities here, all appear to trace back to normal. But, here are the details for you to consider to see if any apply to you.
1. If you have the tracks in an opened configuration and in a specific "Track Display Style", normally there is a yellow/orange line (called rubberband) that runs horizontally through each clip. For a video clip, that line represents Opacity. For an audio clip, that line represents Volume.
You can get other looks for "Track Display Style" by clicking on a filmstrip icon to the left of the name of a Video track or by clicking on the speaker icon to the left of the name of an audio track. Video track has 4 possible Track Display Styles, 3 have the yellow orange line, 1 has a black line. Audio track has 2 possible Track Display Styles, one with yellow orange line, one with black line.
So it could be that you were using a different "Track Display Style".
Black video (being video) would have 4 different Track Display Styles possible as I described above.
So two main thoughts for now
1. Check for opened versus closed Soundtrack and other.
2. Check for Track Display Style.
Please check out these two ideas. I will supply screenshots if necessary to make sure I am in sync with your question.