Weird brightness/gamma issue with Media Players

I’ve just transferred an entire project from one machine to another, and now having a strange issue with Media Players not present on the original machine.

The original machine is a 17" Late 2011 Macbook Pro, the new machine is a 2013 Mac Pro. Both running the same version of UE4 (4.11.2).

Here is a small sample of what the video should look like:


On the original machine, the video looks like this in the Media Player, Media Texture, Material, and when used in UMG.

However, on the new machine, it still looks like that in the Media Player, but in the Media Texture, Material and in UMG it looks like this:


It’s literally exactly the same project, just opened on a different computer.

Any idea what could be causing this?

Just tested this issue on UE4 4.12 Preview 4 and it no longer seems to be causing this problem.