Cate Desktop, version 0.9.0-dev.7

set_workspace_resource() call raised exception: "Long term average operation expects a dataset with the time coordinate of type datetime64[ns], but received int64. Running the normalize operation on this dataset may help"

An error (code 20) occurred in Cate Core:

Traceback (most recent call last):
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\util\web\jsonrpchandler.py", line 190, in send_service_method_result
    result = future.result()
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\concurrent\futures\_base.py", line 398, in result
    return self.__get_result()
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\concurrent\futures\_base.py", line 357, in __get_result
    raise self._exception
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\concurrent\futures\thread.py", line 55, in run
    result = self.fn(*self.args, **self.kwargs)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\util\web\jsonrpchandler.py", line 267, in call_service_method
    result = method(*method_params, monitor=monitor)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\webapi\websocket.py", line 276, in set_workspace_resource
    monitor=monitor)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\wsmanag.py", line 313, in set_workspace_resource
    workspace.execute_workflow(res_name=res_name, monitor=monitor)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\workspace.py", line 608, in execute_workflow
    self.workflow.invoke_steps(steps, context=self._new_context(), monitor=monitor)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\workflow.py", line 629, in invoke_steps
    step.invoke(context=context, monitor=monitor.child(work=1))
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\workflow.py", line 315, in invoke
    self._invoke_impl(_new_context(context, step=self), monitor=monitor)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\workflow.py", line 977, in _invoke_impl
    return_value = self._op(monitor=monitor, **input_values)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\core\op.py", line 211, in __call__
    return_value = self._wrapped_op(**input_values)
  File "C:\Users\HClifton\AppData\Local\Continuum\cate\lib\site-packages\cate\ops\aggregate.py", line 72, in long_term_average
    ' dataset may help'.format(ds.time.dtype))
ValueError: Long term average operation expects a dataset with the time coordinate of type datetime64[ns], but received int64. Running the normalize operation on this dataset may help