UPDATE: Remote host problem resolved by reading Public-ChangeLog.txt. Exception on exit still happens. Just updated FiddlerCore from Nuget to 4.6.2. Fiddler doesn't accept connections from remote hosts. curl -x http://localhost:8877 works fine on windows curl -x http://192.168.145.1:8877 not working. from remote ubuntu host When exiting fiddler, there is an exception. Screenshot attached Tried all dotnet builds. 2, 3.5, 4 Previous version 4.5.1.0 works fine