[BUG] Preview files randomly invalidated after app restart — green bar turns yellow/red, PP v26
Setup:
- Premiere Pro version: 26.x
- OS: Windows
- RAM: 16GB, integrated GPU
- Scratch disks / preview files: same SSD as project
- Typical format: ProRes timeline, exporting to ProRes
The problem:
I render my timeline to completion — full green bar, everything looks good. I go to export, match sequence settings, tick "Use Previews," and the estimated time is around 30 minutes for a 1 Min video. Typically I get less than a second, so I cancel, restart Premiere, and when I reopen the project the render bar is now yellow and red — meaning Premiere has either partially or fully invalidated the preview files even though they are still physically on disk.
On some restarts the green bar survives intact, or only a few sections go yellow. There's no consistent trigger — it happens randomly across different projects, not just long ones.
What I've tried:
- Redirecting scratch disks to the correct preview folder — sometimes recovers the green bar partially
- Clearing media cache — doesn't prevent it from happening again
- Restarting the app multiple times — inconsistent results, sometimes previews survive, sometimes they don't
None of these are reliable fixes. The only guaranteed solution is re-rendering the entire timeline, which is not practical on longer projects.
What I suspect:
Premiere seems to be losing the reference to existing preview files on relaunch rather than validating them against what's on disk. Given that the files are physically present and the scratch disk path hasn't changed, this feels like a cache indexing or session state bug — not a storage issue. The fact that the export with "Use Previews" was estimating 30 minutes even with a full green bar also suggests Premiere wasn't actually using the previews correctly before the restart either.
Ask:
Is there a way to force Premiere to re-index existing preview files without re-rendering? Is this a known issue in v26? Would love to know if there's a log file I can pull to help diagnose this further. Happy to provide project details, sequence settings screenshots, or anything else that helps. This is happening too regularly to ignore.