Changing FQDN, I made a full backup of a running 3CX V15.5 SP1 system on Windows. After restore, during license activation I got the following error, DNS is 126.96.36.199: Can somebody advise me what to do ? I will try installing V15 and upgrade it, if backup from v15,5 can be restores to v15 PBX. At least V15 was installing on this machine without issue. The Windows server is 2008R2, all updated applied.