I spent a few days working this out. I moved my project to a new PC, and UE5.1.0 kept crashing at random intervals, with seemingly random error error messages. I narrowed it down to the ‘iCue’ software that came with the PC, which controls the fan/motherboard LEDs etc. As soon as I disabled that, it’s fine.
Hey there @BradAus28b! Glad you got it sorted! Just a bit of a heads up for everyone who finds this thread in the future: any motherboard or GPU utilities that manipulate memory can cause this issue. Common ones are Rivatuner, Shadowplay, and MSI afterburner. I didn’t know iCue had done it until this post.