Fixes → Apple USB service
Apple Devices is installed, but its USB service is not running
Your iPhone appears in the Apple Devices app. No debugging tool can see it. Nothing reports an error that names the cause. The thing to check is whether port 27015 is listening.
You are in the right place if:
the phone shows up in Apple Devices (or iTunes) and charges normally, but ios_webkit_debug_proxy, a debugging app, or anything else that talks to the phone reports no device, often as “no devices found”, an empty list, or a connection that times out with no explanation.
Check it in one command
In PowerShell:
Test-NetConnection 127.0.0.1 -Port 27015
TcpTestSucceeded : False means the service is not running, and that is the whole problem. If it returns True, your issue is further along the chain. See the proxy returning no targets.
Where this sits
- This PC Windows verified
- Apple driver usbmux failed
- Debug proxy WebKit bridge not reached
- iPhone over USB not reached
- Safari Web Inspector not reached
Everything past the driver is unknown, not broken. It has not been reached yet. That distinction matters when you are guessing which of nine things to fix.
The fix
- Launch the Apple Devices app once, and leave it open. On a Microsoft Store install there is no Windows service you can start from services.msc; the app itself is what brings the background service up. This is the step almost everybody misses, because the driver is installed and every guide assumes installed means running.
- Re-check the port. Run the Test-NetConnection command above again. It can take a few seconds after the app opens.
- Restart whatever was trying to reach the phone. A proxy started before the service came up will often keep answering with a stale, empty device list rather than retrying. Stop it and start it again.
- If the port still does not open, install the iTunes desktop version from Apple's site instead of the Store version. It registers a real Windows service, Apple Mobile Device Service, which you can then start and set to Automatic in services.msc.
Why it happens
Apple's USB driver stack has two halves: the driver, and a background service that brokers access to it. Installing the app installs both, but the Store-packaged version starts the service on demand rather than at boot. A machine that has been restarted, or where the app has never been opened since installation, therefore has a fully installed driver and nothing listening.
Nothing downstream can tell you this, because nothing downstream can see it. From the proxy's point of view there is simply no device, which is also what it would report if the cable were charge-only or the phone were untrusted. Three different problems produce one identical message.