If an autolaunch flow gets failed then default message is displayed i.e An unhandled fault has occurred while processing the flow. Please contact your system administrator. Can we alter this message in anyway ?

I have a need for a feild in an object which accepts only unique values for each record created or updated. So, i want to achieve this using process builder to trigger when ever a new record is created and flow to check if that unique field is not having the value which has been entered. Can anyone help me with this ?