xcodebuild prints this when it installs Mobster’s helper and iOS won’t launch it. Mobster shows On the iPhone, open Settings › General › VPN & Device Management and trust your developer app, or Mobster's helper needs a refresh: its signature expired.
Why it happens
Two causes print the same line. Either the phone doesn’t trust the developer app yet, or a free Apple Account’s signature, which lasts 7 days, has run out.Fix
- On the iPhone, open Settings › General › VPN & Device Management.
- Select your developer app and tap Trust.
- If it’s already trusted, refresh the helper: in Mobster for Mac, open Devices, the iPhone’s card, then Refresh now. Mobster also refreshes it while the phone is plugged in and unlocked.
- Without the app, run the guided setup’s
setup /build.
Check it worked
mobster doctor prints no ✗ line for the runner and the helper answers at http://127.0.0.1:8100. See also the runner’s signature expired.
Checked 26 Oct 2026 against Mobster 0.4.0. Back to Troubleshooting.