Issue after leaving current iMessage conversation on Xcode Simulator

I was creating a sticker pack and after inserting the images, I ran a simulation. It was working until I hit the back arrow to respond to my self and I got this error message:

  libsystem_kernel.dylib`mach_msg_trap:
  0x7fff523b6250 <+0>: movq %rcx, %r10
  0x7fff523b6253 <+3>: movl $0x100001f, %eax ; imm = 0x100001F 
  0x7fff523b6258 <+8>: syscall 
-> 0x7fff523b625a <+10>: retq (Thread 1: signal SIGKILL)
  0x7fff523b625b <+11>: nop

That fifth line keeps being the problem. Whenever I try going back into one of the conversations, the stickers no longer seem to work. I click or drag them and nothing happens. I am running Xcode v11.3. Thanks