Invalid Data Source crashes Visual Studio

Binding data object to a WinForms control is usually straightforward. Say you have a ComboBox control. Clicking the triangle on the top-right will display the ComboBox Tasks dialog.


Once you check the box to "Use data bound items" you start by selecting the Data Source. Normally, clicking the Data Source dropdown provides you with a list of existing items, as well as the option to create a new one. A few days ago we ran into an issue where, instead of the datasources list, we were given this rather entertaining dialog


With a few hints from the blogging community, we were directed to the Data Sources window (Data > Show Data Sources, or Shift+Alt+D.)


Notice the first entry has an error icon. This is due to a datasource pointing to a non-existent class. Right-click the invalid entry and choose Remove Object. Now the Data Source dropdown behaves as expected.