Unable to set unique field to true on one of the user table column

[VishalC3]

Hi,

I am getting error while trying to make one of the user field (email or employee id) as unique. Objective is to make sure perticular column doesnt accepts duplicate values. 

I know this can be done by before business rule too but would like to use OOB approach. 

Thanks,

Vishal

[VishalC3]

Both fields are already in the database indexes and it doesnt work.