As I also posted in the Dorico forum:
How about temporarily moving /Users/USER/Library/Application Support/Propellerhead Software/*/REX Shared Library.bundle out of the way?
From the crash dump I can see that that library gets loaded in, so it must exists on your system.
No
Cubase still crashed and Dorico comes with same fault?
Because Dorico also does not work for Andy, he opened another thread in the Dorico Forum, where we already gave the advice with the Safe Start Mode, but it did not make any difference.
Here’s the other thread: Doeico 3 died - #46 by Ulf - Dorico - Steinberg Forums
Ulf, I think he has something hosed up there. All the things done should have resolved this
Resolved, Andy had some version of VSTConnectPro installed which caused the issue. Simply deleted that one and now all is good. 
Strange that Halion Sonic SE was showing as the crashing thing
Well, it’s like this: At startup Cubase tries to load all plug-ins and see what is in there and if they are all valid. Then they get unloaded again and only loaded again if really needed in a project. So it is some kind of scanning that takes place during startup.
Then VSTConnectPro gets loaded and unloaded, but it does something wrong, in that it unloads a shared library needed also by others bundles. Then the next plug-in gets loaded (in this particular case HSSE) and falls over because of the wrongdoing of the previous plug-in.
It’s all logical in the end, but difficult to figure out 
Hi,
Thank you very much for the clarification, Ulf. And sorry for my poor knowledge.
Thanks for clarifying