How to check flow when customization of form changed by someone in creation of room mailbox

Hi all,

I am very new to ARS and recently come across this tool. we are using ARS 6.9 version and while creating Room mailbox account in my mail domain , I am getting error message that -"the server is unwilling to process request, Administration services encountered an error when creating an object 'cn= <path of the object>'. The specified value already exist.Exception from HResult: 0x80072083)

There was some customization in mailbox creation and one of my team member unwillingly select Customization - reload default on web interface.

Few options i added referring some previous snapshots but still it is showing above error while creating mailbox. I would be thankful if someone can help me. 

Thanks