Likely has something to do with Sol's burst. I've been observing really weird stuff in her animation. It first runs the regular animation for me, but for some reason it activates again and deals wind damage, and then there's a burst streak portrait with 2 Sols.
The crash might only happen with full bursts, what might be happening is that if you full burst, the game crashes due to trying to force in 6 portraits (cause Sol's one duplicates). The fix? Don't use Sol, or don't use burst (or full burst, it runs fine if you do a 4 burst or less)
Here's some screenshots of the fuckery:
Wind Sol confirmed! Kappa. Well I just want more versions of Sol's cuteness...
Notice it says full burst when I didn't even use Cthulhu's burst, her meter is still full. And double Sol.