I want to use the multivalue control from MS DevLabs in Visual Studio online.

Specifically, I want to add fields which

1) identify all the customers interested in a feature and
2) who is the first user of the feature

I've installed the control in my account.

I've set up a 'first customer' field which is a pick list.

I've added a multivalue (customers) control which uses 'first customer' as the backing picklist.

HOwever, when I select the second element in the multivalue control I get an error on the page saying that the result ('Co 1; Co2') is not valid in the first customer field.

I remove the first customer field from the form and the same message comes up, but only at the top of the form.

Clearly I'm doing something wrong, but I can't see what!

Any help would be appreciated

I've set up a field with a pic