I am using Cubase 10.0.15 on a PC Windows 10, v 1803, latest updates.
Using Mystery Islands BloX VST Editor for the Waldorf Blofeld Desktop Synth.
When I open the VST Instrument I am asked to Select the Midi Device for the Midi In: and for the Midi Out:.
The Blofeld has USB connection for bi-directional midi data.
When selecting it Cubase shows a warning, see JPG, and creates the crash dump file.
VST BloX does not establish a connection.
However, I also do this on a Macbook Pro, Sierra, same Cubase and the VST connects no problem.
Repeated attempts to find info at the Mystery Islands, creator of the active BloX, as not yet yielded results.
I sent an email to Steinberg Support and included crash-dump files, hopefully they look into it.
I know sometimes Steinberg responds in the Forum so I will include the crash files
Cubase 10.0.15.136 64bit 2019.6.4 22.32.dmp (778 KB)
Cubase 10.0.15.136 64bit 2019.6.6 17.40.dmp (721 KB)