Hi Dave,
Thanks for your interest in Syncfusion products.
I am afraid that I am not able to reproduce the issues, you have mentioned here. Please refer the following steps, that I tried to reproduce it:
1.Created a sample with GGC.
2.Binded it with Collection object
3.It doesn’t throw any exception.
When GGC is binded with Collection object no need to set the DataMember property, It is not needed with Collection object.
I have created a simple sample illustrating the above:
http://websamples.syncfusion.com/samples/Grid.Web/6.2.0.40/Grid_ASP_CollectionObject/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? So that we could sort out the cause of the issue very fast and provide you a better solution.
Regards,
Raji