Error with enumeration while saving Work Item

I have a custom enumeration that will potentially have several hundred values.  So, I add a value set provider and assigned that to the value set for the enumerated type.  When I select the values and try to save I get the following message:

"The requested literal exists in the value set but not in the enumeration set.  Value Set providers are not allowed to create enumerations outside of the enumeration set."

The added the value to the value set provider js and to the enumeration set.

1.  How can I resolve this error?

2.  Is there any way to get a long list of enumerations in the tool without having to do each one manually?