I've also found a "Cannot read property 'length' of undefined" error in the Excel export in 2016.3.914. Switching back to 2016.2.504 clears the error and exporting works.
2) Export to Excel error - The error you received is related to the jQuery version you are using in the project. Please download jQuery version 1.12.3, reference it in your project and this should resolve the error you received when you export to excel.
Kind regards,
Rumen
Telerik by Progress
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