In our implementation of TFS 2010 we have added various custom fields to Change Requests, and some of these are drop down lists of items.
As time has went on some of these items are no longer valid, but are potentially assigned to change requests past and present. Should we remove items from these drop down lists what would be the scenario when opening TFS change requests via Visual Studio / web interface? Would it simply say that we need to update this mandatory field with a new value, or would it start throwing horrible index out of range exceptions?
Ideally I would just test this in a development instance of TFS, but I don't have access to one, and as such I'd be nervous about 'having a go' just to see what happens.
Got the answer myself by eventually just doing it. So I created a brand new field in TFS with a new field reference, this new field displayed all items in my drop down list once imported.
I then saved a TFS change request having selected one of these values, went to the XML file I exported to make the initial changes, remove the selected item, imported the updated WIT, and once refreshed this updated my list.
The originally selected item was still the selected value, but the box was highlighted yellow and the following message was displayed at the top:
The field 'MyFieldName' contains a value that is not in the list of supported values.