Mnova needs to be able to communicate to the license server every three months for the license to be valid, and to do that you need to be physically on-campus, or connected to your University . Mnova only needs read access to your NMR data, so it is convenient to point the data browser at your folder(s) on LUNA so that your data is immediately accessible as soon as it is acquired.
The latest version our license entitles us to use is 16.0.0, so if you are downloading the installer yourself, make sure you download the correct version - anything 17.0.0 and newer will not work. If you are migrating from an older personal license, then Mnova doesn't handle this well - remove all previous licenses using the instruction e.g. for Windows clear all .lic files from C:\Users\<username>\AppData\Roaming\Mestrelab Research S.L\MestReNova\licenses.
We also have a single license for the plugin - ask Dr Geoffrey Akien if you've got an NMR problem that would benefit from this.