Hi,
we are really sorry. Bad communications 
VST Transit is part of Cubase Artist 10! Please check if the installation is correct. The VST Transit component should be installed here
Win : C:/Program Files/Common Files/Steinberg/Shared Component/vsttransit.dll
macOS : /Library/Application Support/Steinberg/Components/vsttransit.bundle
Is it installed?
Thanx,
Michael.