I've seen someone here have had some sort of the same problem, but the sulotions for the fix didn't work.
Problem: I have worked on a project for hours, and did some work on it for a cuple of hours today, when it suddenly didn't want to play the timeline anyone. I've tryed changing audio hardware (device class) back and forth to MME, with no resoult. I've tried to remove transission and effects, but nothing helps. I've also tried to save the project as a new file, with a new name.
I sat here and just looked in to the screen, and eventually it started to play again. I then tried to edit some more, so I cut a small part out of one clip/scene, and it did't want to play the timeline again. It's like there is a forever long lag, and that the PC is having problem with it. But I can't see any issue with my PC, cause it runs fine. Memory is at 44% 13,9/31,9GB the rest is not worth mentioning cause it's super low.
I've opened up other projects and they work fine. So it seems like there is something wrong with the timeline on this specific project.
I've used Premiere Pro for years, and never experienced anything like this before.
Crash, Error or problem, Freeze or hang, Performance
Please tell us your system specs: OS version, Premiere version, amount of RAM, Hardware specs including graphics card and source properties and sequence settings. Have you done any OS or Premiere updates recently?