AE Crashing with Keylight

I'm assuming AE is crashing in conjunction with using Keylight, but if anyone thinks it may be something else, I'm all ears.

Basically, I'm working on a project using some green screen with 4K video, and as I'm scrubbing through the timeline, it's consistently crashing. I'm editing in Premiere, and using "Replace with After Effects composition" to do the green screen and masking work. When I check the memory details, I see the attached screenshot, which seems wild to me. By the looks of it, AE is trying to use 7 trillion GB of memory.

What the heck is going on?