Vectorworks Inc is currently testing the compatibility of Vectorworks 2018 and 2019 with the beta release of Mac OS 10.14 Mojave.
Because the new version of Vectorworks is released before the next Mac OS is officially released to the public, official Vectorworks support for the new Mac OS cannot be established before the public version of the new Mac OS is released.
As of September 12, 2018, the official statement from Vectorworks Inc about Mac OS Mojave can be found here.
We highly advise that you do not upgrade your mission critical Macs to High Sierra until Vectorworks Inc can fully confirm Vectorworks 2018's compatibility.
An operating system compatibility chart can be found here.