Frequent Crashes, Performance Drop & Broken JKL Trimming in Large Feature Film Project

[Dmitry_Suvorov2859]

Hello,

I'm working on a feature film that is still in production, and I've run into a series of critical issues after receiving a new batch of media from the post-production studio. The project was running smoothly before this.

Here are the specific problems I'm facing:

• Sudden Performance Degradation: The entire project has become sluggish. Timeline navigation and playback are laggy and unresponsive.

• Frequent Crashes: Premiere Pro is now crashing constantly, which was not an issue before.

• Broken JKL Trimming (Rolling Edit): When I try to perform a rolling edit trim using the JKL keys, the clip edge moves by 5-10 frames and then immediately snaps back to its original position. However, trimming frame-by-frame using the interface buttons (+1 frame / +5 frames) works correctly. If I create a brand new sequence and copy-paste all the clips from the problematic one, JKL trimming works again, but the issue returns after about 30 minutes of editing in the new sequence.

I have already confirmed with the post-production studio that their workflow for preparing this latest batch of media has not changed.

Project & Workflow Details:

• Media: All footage is 1920x1080 Apple ProRes 422 Proxy. Audio is on-set WAV.

• Workflow: I am working within a Premiere Pro Production.

  • My Production contains an "EDIT" project for my sequences and a "SCENES" project where all footage is organized into bins.

  • I receive new projects from the post-studio containing synced scenes. I add these projects to my Production and then move the scene bins into my master "SCENES" project.

• Clip Types: All clips on the timeline are either Merged Clips or Multicam.

• Effects: The timeline is very simple, with no color correction and only a couple of standard, built-in transitions.

System & Software Specs:

• Hardware: MacBook Pro 16" (M1 Max, 64GB RAM)

• Storage: Working from an external SSD.

• OS: macOS Tahoe 26.0.1

• Premiere Pro Version: 25.5

Troubleshooting Steps Taken:

• I have tried resetting preferences and clearing the media cache, but neither solved the problem.

What's strange is that I'm editing another feature film using the exact same hardware and workflow, and that project has no issues. It strongly suggests that something is corrupting the sequence itself, but I can't identify the cause.

Any help would be greatly appreciated. Thank you.

[Dmitry_Suvorov2859 · Accepted solution]

It turned out the problem was a broken remixed clip somewhere in the middle of the sequence. Once I deleted it, everything went back to normal.