Active Directory User accounts: Callback number is a required field

Hi All,

        I am seeing "Callback number is required field" in one of our environment(UAT), while changing any attribute on some users.  But it worked fine in two environments (Dev, SIT).  Currently in UAT we are using Readonly user for AD domain configuration.

Here is the error:

[810077] Active Directory user accounts: Callback number is a required field.

Version: Q1IM 6.1

There is no Callback number existing in my Mapping.

I appreciate your help.

thanks