In order to fix compilation error
Encountered conflict between 'Reference:mscorlib' and 'Platform:mscorlib.dll'. Choosing 'Platform:mscorlib.dll' because AssemblyVersion '18.104.22.168' is greater than '3.0.1654.0'.
Please open your .csproj file and add this line in first <PropertyGroupSection> like this:
In the coming week DuoCode 4.0 will be released with official VS 2017 15.5 support.