The camera(s) may be offline with the system in recall. The Client will not connect to the site running either on the Processor or a locally connected laptop. Remote Client connections may or may not work. Licensed Modules will not work. You will not be able to VNC locally. The server logs will include many messages of the following form:
WARNING: Stored Hardware Id 00E04B5C2706 and Interpreted Hardware Id NLD2K0084 don't match
where the Interpreted Hardware Id begins with `NLD`.
After reading the Changelog for 6.7 carefully, use an update stick to update the Processor to 6.7. Note that the 6.7 built-in repair mechanism will reboot any faulted Processor an extra time. Please be patient and allow the process to complete; it may take up to 9 minutes.