You may want to ask in the Premiere Elements forum. This is the Premiere Pro forum. They are different programs.
Maybe a mod will move this for you.
Be prepared to supply more information:
The specified item was not found.
Please give more details about this line that is frozen....
a. Are you referring to the yellow orange line that runs horizontally across the audio or video clip middle?
b. Could you mean the Timeline Indicator that moves from left to right during playback of the Timeline content in the Edit area monitor?
Does this happen in a new project?
Are you seeing this now in an existing large project that you have saved closed and reopened?
Please give more details and we will work with you to resolve this matter.