Custom action crashing Photoshop

I created a custom action for cutting my workload done when optimising images. Everything works fine for a while but then it starts crashing photoshop as soon as I click the play button and every time after that it crashes when I go to use it. It's quite a large action in terms of how many things its doing, but its pretty straight forward stuff, nothing too heavy so I can't see what it's causing it to crash.

Does anybody have any ideas on why its doing that or ways to fix it?

Thanks!