I just checked, for very old server version, it should generate an error. Anyhow, you should upgrade to a supported version (through each major version NC 11 -> NC 12 -> NC13 -> …-> NC17 (-> NC18)). At each step, check out which php version is still supported. Login after each upgrade, check if all apps you are using are activated. Don’t forget to do a backup before all of that.
The problem is, if you find a problem with an unsupported version, there is nobody that will fix it. There are chances as well, that some things were fixed since then.