Video Preview: Transition effects cause 'Media Pending' when the file format is 'I-Frame Only MPEG'

[isabellad1450529]

I'm running windows 11, on  premiere version 25.5.

System Model Z690 AERO G DDR4

Processor 13th Gen Intel(R) Core(TM) i5-13400F, 2500 Mhz, 10 Core(s), 16 Logical Processor(s)

Installed Physical Memory (RAM) 96.0 GB

GPU NVIDIA GeForce RTX 4070

Rendering a video preview in file format 'I-Frame Only MPEG' causes media pending errors where I use a transition in the timeline. I've got Maximum Bit Depth, Maximum Render Quality, Composite in Linear Colour checked. If my file format is anything else this doesn't happen. 

I can use the trick to enable and disable the footage to fix this everytime, but it's not a great sollution. 

Any advice would be useful, as I'd prefer to preview my footage in this file format. 

Thank you,

[Ann Bens]

Turn off composite in linear color

best is to usu quicktime prores lt for pteview

[isabellad1450529]

The issue still persists, I can confirm I've tried turning off composite in linear color. 

Why is it best to use Quicktime ProRes for previews? Understand it's best for playback, that's why I use proxies, but the files are much larger in comparison to  'I-Frame Only MPEG.' Open to changing my workflow if it really is better though...  

[R Neil Haugen]

The reason the files are bigger is because they are far less compressed. Which leaves far less for the system to do to get playback up to speed. And in my personal experience, fewer hassles.