Nicolas Goutte

The aforementioned article reads at the end: "In addition to the release of Vectorworks 2019 SP1, we are also working on a macOS Mojave service pack for Vectorworks 2018. We hope to have it available later this fall." I suppose that this quote was meant by @Neil Barman

Ah, OK, file right issues.

Yes, I had it once. Installing again (in another folder) had solved it for me, as the new installation did have all the correct files.

As nobody has answered you yet, I will give it a try. - have you enough free space on the destination volume? - perhaps you should try to repair the installation to VW 2019 SP0 and then try again to update. For going back to VW 2019 SP0 see the following post:

'Gratitude' is a two-way thing, which does not include the dismissal of the personal competence of Vectorworks staff.

Can we avoid to become personal, please?

Personally in such a case, I would simply re-install. May-be you will have to move away (while VW does not run) your VW 2019 user folder so that it is re-created by the next start.

See on the main thread for macOS 10.14 compatibility:

My direct boss @Hans Martin Kern suggests that you should contact ComputerWorks for getting that SDK. And yes: that special SDK is not binary compatible to the regular SDK. (The English VW still uses the regular SDK.)

448893 is a special SDK, released by the German online update of last Monday. (As I am not an employee of ComputerWorks, I will not tell more, esp. in public. Sorry.)

Good, if you use VW SDK 2019, that is another story, then you must use toolset V141. The bad news is that under Windows you cannot use Debug version of your plugin in a released VW version... which is compiled as Release. That is has to do with a design choice of Microsoft where the C Runtime of Debug and Release cannot be used together. As, since VW 2018, TXString ist implemented internally as a std::string, you cannot call a TXString from your plug-in through a call using a TXString in VW. Yes, it is super-annoying. You have to fake debug, by using a release target without Optimization. Yes, that means that Edit&Continue and other features working only in Debug cannot be used.

I am not from Vectorworks either, but you can check the compatibility list. As already macOS 10.13 is not supported for VW 2016, there is little chance macOS 10.14 will ever be (for VW 2016).

If you use VW SDK 2017 or 2018, you still need to use the toolset v110 of Visual Studio 2012, as the VW SDK is compiled with it. You can use the IDE of Visual Studio 2017 (I do too, as the new Visual Studio is much more comfortable), but you must use the old toolset. I am surprised that you managed to even link the code.

I do not know why the last started VW has the priority but it has been that way since a few years. However it is not always so, sometimes/often you get the dialog telling that the serial number is in use. Yes, it bites me from time to time, when I forgot that my other computer (Mac/Windows) has already a VW started, especially it seems if the other VW has been busy doing something.

You can use a non-network license only on one computer at a time, including using another VW version, e.g. 2017 vs. 2018. (I really mean "use", not "activate".)