When creating custom code, I have the option "Create Descriptor" selected. When I run the app, I get an error that says I may be missing a custom descriptor.

With this option selected, do I still need to do this? If so, what does this option do?

OK, it was creating the descriptor properly when the checkbox was checked, but it was not adding the descriptor to the PropertyDescriptors collection within the business object, so I corrected the problem and it will be in the next update.  But, like I said, that workaround will work until we get you another update.