More follow up information… the problem returned, but I believe I solved it. I think the bug arises from me using/changing parameters in the statetree that are already referenced.
I think the parameters on a statetree (correct me if I’m wrong) are stored in a struct which I know can be buggy in blueprints. So eventually when I compile them and the serialization messes something up, it leads to the null pointer ACCESS_VIOLATION (I think this is consistent with the previous statetreecompiler issue as well with assertionfailed getscriptstruct). The mini crash dump throws me a 0xc0000005 error code which also implies mismatched memory.
I have remade the same statetree without parameters and removed the old one and haven’t crashed. For people reading this encountering a similar issue you could try removing the parameters on your statetree or doing the parameters for the statetree in C++ (which I think shouldn’t have the same issues). For now my workaround is just passing the values I need from the owner of the statetree to the statetree itself (though this will require you to hard reference the owner’s class in the statetree)