This may be a proxy-related issue. To resolve this please follow the below steps:
1. Add the following system environment variable in windows
Variable name: SPECFLOW_PLUS_USE_PROXY_CREDENTIALS
Variable value: 1
2. Restart the application
If you run the tests with Visual Studio please restart your Visual Studio (exit, open again).
This is necessary to pick up the new environment variable setting.
3. Run the SpecFlow+Runner tests again