exception when calling speakeasy's "call" api

[jtbennett-fe]

File "speakeasy/speakeasy/binemu.py", line 324, in set_func_args
self.mem_write(curr_sp, r)
File "speakeasy/speakeasy/memmgr.py", line 194, in mem_write
self.emu_eng.mem_write(addr, data)
File "speakeasy/speakeasy/engines/unicorn_eng.py", line 196, in mem_write
return self.emu.mem_write(addr, data)
File "python3.7/site-packages/unicorn/unicorn.py", line 442, in mem_write
raise UcError(status)