I have successfully created Contacts via Web Service that each contain a
unique identifier in a custom field named 'MyKeyField'. Now I need to
retrieve a Contact with a specific value in the aforementioned custom field
'MyKeyField'. Unfortunately, this does not work.

Here is a simplified C# snippet of the code I use to retrieve one specific

GroupWise.FilterEntry fe = new GroupWise.FilterEntry();
fe.op = GroupWise.FilterOp.eq;
fe.custom = new GroupWise.Custom();
fe.custom.field = "MyKeyField";
fe.value = "SomeKeyValue";

GroupWise.getItemsRequest req = new GroupWise.getItemsRequest();
req.filter = new GroupWise.Filter();
req.filter.element = fe;

Can anyone please tell me how to do that correctly? Thanks in advance.

Best regards,