ID 586254 - A crash occurs when selecting a custom XML preset from the Build Track From Export Structure on the timeline in Nuke Studio/Hiero

Problem summary
A crash occurs when selecting a custom XML preset from the Build Track From Export Structure on the timeline in Nuke Studio/Hiero.
 
Customer reported version
Hiero 15.1v1
 
Customer reported platform
Rocky 9
 
Steps to reproduce
1) Download the customer attached PY and XML files,
2) Place XML in /.nuke/TaskPresets/15.1/Processors/hiero.exporters.FnShotProcessor.ShotProcessor/
3) Place .py files in /.nuke/Python/Startup/
4) Launch Nuke Studio/Hiero and import footage to the timeline.
5) Right-click the clip in the Sequence, then select Build Track > from Export Structure.
6) Select the GATS_SHOT_TEMPLATE_BASIC preset, then press Cancel.
7) Repeat step 5 to open the Export Structure UI, then select OTIO or any other options, then Cancel
8) Repeat steps 5-7, observing performance in Nuke Studio/Hiero.
 
Expected behavior
The XML template should be selected and applied from the Export menu.
 
Actual behavior
Nuke Studio/Hiero crashes when selecting the Export preset after cancelling a previous selection.
 
Workaround
There is no available workaround at this time.
 
Reproduced by Support in:
Nuke Studio/Hiero 15.1v2 - Windows 10, Rocky 9
Nuke Studio/Hiero 12.2v1 - Windows 10 - regression
 
Earliest version tested
Nuke Studio/Hiero 12.1v5 - This issue doesn't appear in this version and has regressed