assertion failure at Objects/call.c:618: PyObject *callmethod(PyThreadState *, PyObject *, const char *, struct __va_list_tag *): Assertion 'callable != NULL' failed.

assertion failure at Objects/call.c:618: PyObject *callmethod(PyThreadState *, PyObject *, const char *, struct __va_list_tag *): Assertion 'callable != NULL' failed. #10601