Just installed 15.5 and don't have the ability to change the extension for voicemail from 666 to 777 (I know that 777 is used as another system extension, I need this changing also). I saw that you can play with the XML files in a backup zip, then restore from the changed backup. I tried this and it said the restore failed as the backup was not correct. I have reinstalled and uploaded my backup, the option to change the VM extension from 666 is greyed out! 666 is a users extension on a remote PBX that we connect over a bridge! Any way we can change this? We managed it on v15 on our remote PBX but we have upgraded that to 15.5 with no issues (in-place upgrade). Can't find this anywhere online! Any help would be greatly appreciated!