Overview:
An error message appears when saving changes to a Picklist Name Value or Field Name value. These are the API name values and not the labels displayed in the user interface.
Root Cause:
An unsupported character is included in the text for this field.
Solution:
Numbers or lower-case characters can be used in Field and Picklist names. Any other characters entered in this field prevent the saving of changes.
Related Documentation:
Vault Documentation: N/A