mono.exe not found in debug session

[KG2501]

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?