Lots of details lacking.
What version of Premiere Elements are you using and on what computer operating system is it running?
Go back to the Timeline, expand the Timeline with the - + slider over the Timeline so that you can get a good look at the Timeline content.
The most likely problem candidate is a stop marker placed at the end of the last item on the Timeline. If there, get rid of it. You do not need it, and it causes problems.
Next, look at the spacing between Timeline markers.
Next, look for very thin vertical black lines scattered among the Timeline content. If you find them, delete them. They are clip leftovers or fragments that were created by clip movement and other Timeline maneuvers.
Next, look for gaps - misplaced transitions and the like.
Please let us know the outcome.
Thanks so much. I removed the marker at the end of the video and it worked great!
Thanks for the great news of your success.
In troubleshooting there are a lot of variables that need sorting out to get at the core of an issue. We are very pleased to learn that our first round of troubleshooting caught the problem.
A just in case note, if you do any burn to Blu-ray with Premiere Elements do not bother with stop markers at all. Stop markers used in the Premiere Elements Blu-ray disc format on Blu-ray disc are not recognized by the players.
Thanks for the opportunity to help.