When trying to save after selecting a picklist value, an error is received. Error base text is "The follow information does not satisfy validation constraints: ... is not in the validation list." with related information in place of the ellipses.
When a different picklist value is selected and saved, the first value can then be selected and will save on the second attempt.
Pick valueA, error on saving.
Pick valueB, save successful.
Pick valueA, resave successful.
One possible solution to this issue is detailed below.
When adding values to a picklist, the system does not check to make certain the value fits within the character maximum set within the text field on the business object. The reason the save is successful the second time the value is selected is due to the system truncating the text to fit within the allotted character space.
Go to Configure Application
Click Business Objects
Select the appropriate Business Object, eg. Incident.
Click on Fields
Select the field your picklist is populating, eg. Service.
Increase the Text Length for the field so it can accommodate the length of all entries in the picklist.