first_packet = self.connection._read_packet()
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pymysql/connections.py", line 683, in _read_packet
    packet.check_error()
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pymysql/protocol.py", line 220, in check_error
    err.raise_mysql_exception(self._data)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pymysql/err.py", line 109, in raise_mysql_exception
    raise errorclass(errno, errval)
InternalError: (1054, u"Unknown column 'salt' in 'field list'")
[ERROR] 2018-09-24 13:57:27,132 | /home/frappe/frappe-bench/apps/frappe/frappe/utils/error.py:
New Exception collected with id: 2018-09-24 13:57:27.101936-10.0.2.2-449
[DEBUG] 2018-09-24 13:57:55,209 | /home/frappe/frappe-bench/apps/frappe/frappe/utils/scheduler.py: