I don’t consider this a bug as we’re not supposed to be modding this file. This is just something that I noticed that I’m passing along for your information.
I downloaded one of those cross hair images going around and it downloaded as a ‘.jpeg’. I renamed it ‘pimax_default.jpeg’ (I left the extension alone) and, after restarting, I noticed that the Pimax Experience was no longer loading. Just a blank screen.
Changing the file to a jpg (instead of jpeg) made PE show up almost immediately.