Error for Corrections

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-18-6ad445ea486b> in <module>()
      6                                      #'Proximity',
      7                                      'TailCut',
----> 8                                      'TotalProperties'
      9                                     ])
     10     del bla

/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/minitrees.py in load(datasets, treemakers, preselection, force_reload, delayed, num_workers, compute_options, cache_file, remake_cache)
    496 
    497     result = dask.dataframe.from_delayed(
--> 498         partial_results, meta=partial_results[0].compute())
    499 
    500     if not delayed:

/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/base.py in compute(self, **kwargs)
     77             Extra keywords to forward to the scheduler ``get`` function.
     78         """
---> 79         return compute(self, **kwargs)[0]
     80 
     81     @classmethod

/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/base.py in compute(*args, **kwargs)
    177         dsk = merge(var.dask for var in variables)
    178     keys = [var._keys() for var in variables]
--> 179     results = get(dsk, keys, **kwargs)
    180 
    181     results_iter = iter(results)

/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/threaded.py in get(dsk, result, cache, num_workers, **kwargs)
     74     results = get_async(pool.apply_async, len(pool._pool), dsk, result,
     75                         cache=cache, get_id=_thread_get_id,
---> 76                         **kwargs)
     77 
     78     # Cleanup pools associated to dead threads

/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/async.py in get_async(apply_async, num_workers, dsk, result, cache, get_id, raise_on_exception, rerun_exceptions_locally, callbacks, dumps, loads, **kwargs)
    491                     _execute_task(task, data)  # Re-execute locally
    492                 else:
--> 493                     raise(remote_exception(res, tb))
    494             state['cache'][key] = res
    495             finish_task(dsk, key, state, results, keyorder.get)

TypeError: ufunc subtract cannot use operands with types dtype('O') and dtype('<M8[s]')

Traceback
---------
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/async.py", line 268, in execute_task
    result = _execute_task(task, data)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/async.py", line 249, in _execute_task
    return func(*args2)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/dask/compatibility.py", line 47, in apply
    return func(*args, **kwargs)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/minitrees.py", line 378, in load_single_dataset
    run_id, treemaker, force_reload=force_reload, event_list=event_list)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/minitrees.py", line 325, in load_single_minitree
    skimmed_data = treemaker().get_data(run_id, event_list=event_list)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/minitrees.py", line 92, in get_data
    desc='Making %s minitree' % self.__class__.__name__)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/paxroot.py", line 165, in loop_over_datasets
    for _ in function_results_datasets(*args, **kwargs):
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/paxroot.py", line 157, in function_results_datasets
    raise e
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/paxroot.py", line 151, in function_results_datasets
    yield event_function(event, **kwargs)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/minitrees.py", line 75, in process_event
    result = self.extract_data(event)
  File "/project/lgrandi/anaconda3/envs/pax_head/lib/python3.4/site-packages/hax-1.6.2-py3.4.egg/hax/treemakers/corrections.py", line 152, in extract_data
    ts = ((self.run_start - np.datetime64('1970-01-01T00:00:00Z')) /