Batch Fitting throws error (post refactor #3)

[krzywon]

Describe the bug
As noted in #3776, batch fitting is throwing an error in the latest refactoring branch (which is now merged into main). The fit runs, the results window is displayed with all expected parameters, and everything else seems to happen properly. Despite that, the following error is thrown.

ERROR : sas.qtgui.Perspectives.Fitting.FittingWidget (FittingWidget.py:192) :: Traceback (most recent call last):
File "sasview\src\sas\qtgui\Perspectives\Fitting\FittingWidget.py", line 1598, in batchFitComplete
kernel_module = FittingUtilities.updateKernelWithResults(self.logic.kernel_module, param_dict)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "sasview\src\sas\qtgui\Perspectives\Fitting\FittingUtilities.py", line 799, in updateKernelWithResults
local_kernel.setParam(parameter, results[parameter][0])
^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'setParam'

To Reproduce

1. Load 2+ data sets (I loaded the three AOT_*.xml files)
2. Send them to a batch fit tab
3. Select sphere model and scale, background, and radius for the fit
4. Run the fit
5. Error

Expected behavior
No error should be thrown and whatever the error is being thrown for should be corrected.

SasView version (please complete the following information):

• Version: main as of 1/9/2026