While testing IBX-2625 we discovered that the problem with validation occurs in entire system where Identifier field exist. 
Please implement such solution for validation method/methods that solve the problem everywhere.

List of places where Identifier field exist in our system and problem occurs:

Admin > Object States > Creating new Object states group
Admin > Object States > Object state group > Creating new Object state
Admin > Segments > Creating new segment group
Admin > Segments > Segment group > Creating new segment