This is a Fiddler Classic message inspector for MessagePack using Nerdbank.MessagePack.
Run dotnet publish -c Release
It should copy all files from /bin/Release/net48/ into fiddlers Inspectors folder (can usually be located at "C:\Program Files\Fiddler\Inspectors" or "%LOCALAPPDATA%\Programs\Fiddler\Inspectors").
The project requires a reference to your Fiddler.exe file in order to compile.
Make sure to install Fiddler Classic before trying to build the project.
If install location is non-standard then you will probably need to modifyfy the .csproj file and update the path to fiddler executables