I installed Fiddler on a new Windows 10 workstation. When starting up Fiddler, I get the following error message: “Failed to register Fiddler as the system proxy.”
When I try to capture traffic (F12) I get the same error message. No
traffic is captured.
Netstat shows Fiddler is listening:
C:\>netstat -an | find "8888" TCP 127.0.0.1:8888 0.0.0.0:0 LISTENING
After searching high and low, the fix is quite simple. Just go and start the WinHTTP Web Proxy Auto-Discovery Service. It was disabled on my workstation. After that, Fiddler works as expected.