Hi @Clever_mind9131,
Welcome to the Premiere Pro forums and sorry you're experiencing issues. We need a few more details to help with the issue like Premiere Pro version you are on and hardware specs. Please see How to Report a Problem.
Let us know if any of the suggestions provided help. Knowing what effects or files are around that timecode could be very useful. What kind of media are you working with?
Sorry for the frustration,
Dani