VSCode DLS in offline environment?

[Rel]

I'm doing all development in offline environment, so my computer 
doesn't have internet access So I downloaded and installed latest 
DMD, downloaded and installed VSCode extension "VSCode DLS", 
downloaded DLS executable from github and put it into DMD's bin 
folder. When I try to create and edit d-file in VSCode i get the 
error:

Starting client failed
Error: unsupported server configuration {
     "command":""
}

at main.js:356:35

How can I fix this? Also how do I install dub packages in offline 
environment?