Scheduled Scrub not running

Deleted and re-added, still getting an error. This is the email contents on the failed cron scrub job

Cron <root@rocky> /opt/rockstor//bin/st-pool-scrub 4 \*-*-*-*-*-*

Traceback (most recent call last):
  File "/usr/lib64/python2.7/logging/handlers.py", line 76, in emit
    if self.shouldRollover(record):
  File "/usr/lib64/python2.7/logging/handlers.py", line 154, in shouldRollover
    msg = "%s\n" % self.format(record)
  File "/usr/lib64/python2.7/logging/__init__.py", line 724, in format
    return fmt.format(record)
  File "/usr/lib64/python2.7/logging/__init__.py", line 464, in format
    record.message = record.getMessage()
  File "/usr/lib64/python2.7/logging/__init__.py", line 324, in getMessage
    msg = str(self.msg)
TypeError: __str__ returned non-string (type list)
Logged from file pool_scrub.py, line 78
Traceback (most recent call last):
  File "/usr/lib64/python2.7/logging/handlers.py", line 76, in emit
    if self.shouldRollover(record):
  File "/usr/lib64/python2.7/logging/handlers.py", line 154, in shouldRollover
    msg = "%s\n" % self.format(record)
  File "/usr/lib64/python2.7/logging/__init__.py", line 724, in format
    return fmt.format(record)
  File "/usr/lib64/python2.7/logging/__init__.py", line 464, in format
    record.message = record.getMessage()
  File "/usr/lib64/python2.7/logging/__init__.py", line 324, in getMessage
    msg = str(self.msg)
TypeError: __str__ returned non-string (type list)
Logged from file pool_scrub.py, line 39