Error undocking slice viewer in Reflectometry GUI

[adriazalvarez]

Found in Manual testing: #40692

This error seemingly happens when you undock the slice viewer. I've been able to reproduce it consistently on windows and macos but I'm not sure what is causing this, there is also a second error when loading the test data (may be related?).

Also reproducible in 6.14, so not a regression.

Error message:

Traceback (most recent call last):
  File "/Users/datanes/miniforge3/envs/mantid-developer/lib/python3.11/site-packages/matplotlib/cbook.py", line 298, in process
    func(*args, **kwargs)
  File "/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/mantid/plots/resampling_image/samplingimage.py", line 93, in _resize
    xbins, ybins = self._calculate_bins_from_extent()
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/mantid/plots/resampling_image/samplingimage.py", line 98, in _calculate_bins_from_extent
    bbox = self.get_window_extent().transformed(self.axes.get_figure().dpi_scale_trans.inverted())
                                                ^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'get_figure'

To Reproduce

1. Open Reflectometry GUI
2. Navigate to Reduction Preview tab.
3. On Run field type: INTER45455 and push the button Load. It should load the run on the slice viewer docked widget.
4. Inmediately push again the Load button.
5. Try to undock the slice viewer widget window (top left corner)

6. Error message.

Additionally, when loading the data (Inter45455) I always seem to get this error :

Error in execution of algorithm ReflectometryReductionOneAuto:
Instrument: Detector with ID 1001 not found. search object ''
Error in execution of algorithm ReflectometryISISLoadAndProcess:
Instrument: Detector with ID 1001 not found. search object ''
  at line 110 in '/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISLoadAndProcess.py'
  caused by line 653 in '/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISLoadAndProcess.py'
Error starting batch algorithm
Error performing reduction: Instrument: Detector with ID 1001 not found. search object ''
  at line 110 in '/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISLoadAndProcess.py'
  caused by line 653 in '/Users/datanes/mantid-mac/mantid/Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISLoadAndProcess.py'

Although this doesn't affect any further action on the interface.

Additionally:
Expected behavior

Screenshots

Platform/Version (please complete the following information):

• OS: Windows, macos
• OS Version:
• Mantid Version 6.14, nightly

Additional context