I wanted to share with you additional test results in hopes of expediting resolving this issue.I read in one of the post on the formum that the gridpicker valuemembepath attribute and datagrid mappingname needed to be set to the same attribute name. I also updated the ItemSource of the gridpicker to the TestTypeInfoCollect. Lastly I set the DisplayMemberPath to TestTypeShortDescription. Please see the xmal image below:I updated the TestInfoViewModel, moving the LoadTestTypeInfo into LoadTestInfo. This change was required to populate both collections.See image below:I set a break point after the LoadTestInfo successfully complete. The quick watch shows the information stored in the collection. See image below:The next image shows the TestTypeInfoCollection info:When I run the application I get the following exception.I appreciate your assistance in resolving this matter.