EXC_BAD_ACCESS on CreateMaterial()

I've just built my iOS app, but one I start building the app just crashes and gives me a EXC_BAD_ACCESS code. It's within the CreateMaterial function, but other than that i've not received much more info.

Here's the breakpoint:

 0x100912158 <+36>:  orr    w0, wzr, #0x4
     0x10091215c <+40>:  bl     0x10091371c               ; ::CreateObjectFromCode<Unity::Material>() at BaseObject.h:1178
     0x100912160 <+44>:  mov    x21, x0
     0x100912164 <+48>:  ldr    x8, [x21]
     0x100912168 <+52>:  ldr    x8, [x8, #88]
     0x10091216c <+56>:  mov    x1, x19
     0x100912170 <+60>:  blr    x8
     0x100912174 <+64>:  mov    x19, x21
     0x100912178 <+68>:  ldr    x8, [x19], #56
     0x10091217c <+72>:  ldr    x22, [x8, #72]
 ***->  0x100912180 <+76>:  ldr    x8, [x20]  BREAKPOINT HERE***
     0x100912184 <+80>:  ldr    x8, [x8, #64]
     0x100912188 <+84>:  mov    x0, x20
     0x10091218c <+88>:  blr    x8
     0x100912190 <+92>:  mov    x1, x0
     0x100912194 <+96>:  mov    x0, x21
 

So as you can see it's not really clear to me what the exact problem is. The editor itself isn't giving me info and the game just runs fine on there.

Anyone else with the same problem? Or someone who knows how to fix this?