mono.exe not found in debug session

I have Visual Studio Code 1.41.1 installed with latest Mono-debug.
When I start debugging I get the following error:
mono --debug --debugger-agent=transport=dt_socket,server=y,address=127.0.0.1:50046 cscs.exe -d -inmem:0 -co:/debug:pdbonly -ac:2 c:\Users\Administrator\AppData\Roaming\Code\User\cs-script.user\new_script.cs
'"C:\Users\Administrator\AppData\Roaming\Code\User\cs-script.user\mono.exe"' is not recognized as an internal or external command,
operable program or batch file.

When I open a cmd.exe and enter just mono.exe I get the help for mono. So my path variable is correctly set to:
PATH=C:\Program Files\Mono\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Program Files\Microsoft VS Code\bin;C:\Program Files\dotnet;C:\Users\Administrator\AppData\Local\Microsoft\WindowsApps
Why does visual studio code try to start mono.exe from the script directory? And why is there a double backslash before mono.exe?

Start by reproducing the debug session described in the issue and compare the command's resolved mono.exe path with the reported PATH. Investigate how the debug adapter chooses the script directory and handles the doubled backslash; done means a session can launch mono from the configured installation without requiring mono.exe in the script directory.