@the-ress thanks, this actually seems to fix not being able to launch VSCode from a UNC path in general (not just portable).

@bpasero I have checked, and found that code-insiders (2ab82c12ed809fd1df921d016eed344a18a9ee8f from 2019-01-14T06:18:47.017Z`) could not be launced from an UNC path.

$ code-insiders 
'\\server\c$\Scripts'
CMD.EXE was started with the above path as the current directory.
UNC paths are not supported.  Defaulting to Windows directory.

@fbehrens when I tried it worked for me, I used a localhost UNC path (see https://stackoverflow.com/questions/2787203/unc-path-to-a-folder-on-my-local-computer), opened it in Windows explorer, copied Code over and tried to start it. This works after this change but not before this change.

@fbehrens you should be able to launch Code - Insiders.exe directly. code-insiders.cmd can’t support (most?) UNC paths because it’s run by cmd.exe. There’s a separate issue for that: #53764

@the-ress thanks for mentioning, that's working indeed.

When invoking Code - Insiders.exe from powershell you need to type & "Code - Insiders.exe".

This is because of the spaces. I suggest to remove the spaces from the EXE filename.

Code.CMD supports UNC paths, AS LONG as you do not pass relative arguments. The message you see is just a warning. See #53764 (comment).