[LDAP] Map Usernames using Advanced Query gives Unhandled Exception in userToDNMapping

In userToDNMapping, when using the advanced query option for mapping the usernames, it gives an unhandled javascript error when the match expression is set as below.

^([a-zA-Z0-9])(([\-.]|[_]+)?([a-zA-Z0-9]+))*(@){1}[a-z0-9]+[.]{1}(([a-z]{2,3})|([a-z]{2,3}[.]{1}[a-z]{2,3}))$

Please refer the image attached for the same.