This is aimed at Premiere Pro, but may help
Work through all of the steps (ideas) listed at http://ppro.wikia.com/wiki/Troubleshooting
If your problem isn't fixed after you follow all of the steps, report back with ALL OF THE DETAILS asked for in the FINALLY section, the questions at the end of the troubleshooting link... most especially the codec used... see Question 1
What kind of camera or camcorder is your video coming from and how did you get it into your computer?
Which settings did you select when you started your Premiere Elements project?
Have you ensured that you have the latest drivers for your graphics card from the ATI or nVidia web site? Have you ensured you have the latest version of Quicktime?
I had no trouble with the clips until I added a transition. When I try to delete the clip and reinsert is from organizer, it just makes the next few clips also black out. I have looked at the timeline to see where it is on the list of video and audio channels but see nothing different from the rest of the movie footage. I had also added sound track material that is now cutting out. Where can I see the explanations for the timeline/
Have you rendered your timeline (pressing Enter) after applying a transition or effect to it?
Rendering the Timeline will basically write an AVI file, that will be used for the best possible playback of that Timeline.
With much material, the Video is in GOP (Group of Pictures) format, and for frame-accurate editing, one needs full I-frame format. This ARTICLE will give some background.
When editing GOP structure material, one can Cut within the GOP structure, and then there is no I-frame to reference, so the "difference" frames do not have all of the necessary info. Usually, the program will internally convert to I-frame for editing, but there are times that this does not work perfectly, so Rendering will essentially do that conversion for you.
In some cases, Rendering is not really necessary, and I do many Projects (mostly DV-AVI material), where I never Render. Other times, I might well Render a particular area dozens of times, to see the best display in playback.
Thanks, but how do you initiate rendering? When I press enter, it takes me
back to the beginning but I can't see that it is rendering.
Pamela F. Pressel
One initiates the Rendering process by hitting the Enter key, as you note. If there is no Rendering taking place, then a couple of things might be in play:
1.) your footage has already been Rendered (or does not require Rendering), and there should be a green line (or no line) above the Clips in the Timeline View Mode
2.) your WAB (Work Area Bar) has been set to a portion of the Timeline, which has already been Rendered
PS - for a look at the WAB, this might be useful: