I've created a sample feature report template. The template was created successfully. But An error occurred while generating report(s).
I tested different options and discovered a problem with layer.Name: Error: Cannot read property 'layerName' of undefined.
The template was not changed.
Thanks for the screenshots and steps. Are any of the layer names in your feature service duplicated? Do any of the layer names contain special characters? If possible, could you please provide the feature report template DOCX file and survey XLSForm to help with troubleshooting?
Just updating this thread with the outcome of our discussion by email. The error was caused by a duplicate name in the XLSForm, specifically a begin group element that had a text question inside it with the same name. Making these names unique solved the issue. Our team has made improvements to the feature report template logic to better handle this and the fix will be included in the next release.
Thanks again for reporting it.