Thank you for the detailed explanation.
I have reproduced the issue on my side and we will provide a fix for it with the upcoming service pack - scheduled for 17th this month. I have modified the CustomizationView.xaml file from the TreeView Customization example with all changes needed. Please replace the content of the CustomizationView.xaml file with the attached one and let me know if you continue getting this error.
Looking forward to your reply.
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