Hi Patrick,
Thank you for your details.
I am afraid that I was not able to reproduce the exception. I have created a sample to test the issue and it is available in the
following link.
http://websamples.syncfusion.com/samples/Grid.Windows/F68169/main.htmPlease have a look at the above sample and if still the issue exists, could you please try reproducing it in the above sample or
send us the reproducing steps so that we could sort out the cause of the issue and provide you a solution?
Thank you for using Syncfusion Products.
Best Regards,
Jeba.