> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mobster.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Unable to launch app.mobster.wda.runner.xctrunner because it has an invalid code signature, inadequate entitlements or its profile has not been explicitly trusted by the user.

> iOS refused to start Mobster's helper because you haven't trusted the developer app, or its 7-day signature expired. Trust it, or refresh it.

You see this: `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

1. On the iPhone, open **Settings › General › VPN & Device Management**.
2. Select your developer app and tap **Trust**.
3. 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.
4. 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](https://docs.mobster.dev/troubleshooting.md#runner-expired).

Checked 26 Oct 2026 against Mobster 0.4.0. Back to [Troubleshooting](https://docs.mobster.dev/troubleshooting.md#iphone).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.