iMessage Is Signed Out on iPhone: How to Fix It
Fix the iMessage Is Signed Out error on iPhone by checking Apple Account sign-in, activation, connectivity, and settings—without erasing your messages.
If an app suddenly disappears and drops you back to the Home Screen on iOS 15, the app has most likely crashed. A crash can come from a bug in the app, an outdated app build, a temporary iOS problem, damaged local app data, or a device that is short on free storage. If only one app is affected, troubleshoot that app first. If many apps—including Apple apps—are closing unexpectedly, focus on iOS, storage, and the device itself.
Apple’s current guidance for an app that closes unexpectedly is to close and reopen it, restart the device, check for app and system updates, then delete and redownload the app if needed. That order is safer than jumping straight to a factory reset. See Apple’s official troubleshooting steps for apps that close unexpectedly.

Start with the simplest fix. On an iPhone without a Home button, swipe up from the bottom and pause to open the App Switcher. On an iPhone with a Home button, double-click the Home button. Find the problem app, swipe up on its preview, then open it again.
Do this for the app that is misbehaving, not every app on the phone. Apple notes that force-closing apps unnecessarily can make them take longer to reopen because their data must be loaded again.
A restart clears temporary system state that can contribute to repeated crashes. A model-independent method on iOS 15 is Settings > General > Shut Down. Drag the slider, wait for the iPhone to turn off, then hold the side button until the Apple logo appears. After the phone starts, try the app again.
If one or two apps are crashing, an app update is one of the most important fixes. Open the App Store, tap your profile picture, and look for available updates. Tap Update beside the problem app, or update all apps. Apple says App Store apps normally update automatically, but you can also update them manually; see Apple’s manual app update instructions.

If no update is offered, the developer may not have released a fix for iOS 15, or the newest version may require a later iOS release. Check the app’s App Store page for compatibility information.
If the app is current but still crashes, go to Settings > General > Software Update. Install the newest iOS version offered for your iPhone. If your model can upgrade beyond iOS 15, moving to the latest supported release can provide bug fixes and newer app compatibility. Apple recommends backing up before a system update and provides the current process in its iPhone and iPad update guide.

Very low free space can cause broader performance problems. Open Settings > General > iPhone Storage and review the available space and Apple’s recommendations. Apple advises keeping at least 1 GB of free space to avoid slowdowns. If storage is tight, remove large downloads you no longer need or offload unused apps. Apple explains these options in its iPhone performance guidance.
If the crash is limited to one app and updates did not help, reinstalling it can replace damaged local app files. Touch and hold the app icon, tap Remove App, then Delete App. Reinstall it from the App Store afterward. Apple warns that deleting an app can remove data stored only inside that app, so confirm that important data is synced or backed up first. Deleting an app also does not automatically cancel its subscriptions. See Apple’s app deletion instructions.

If several unrelated apps, including built-in Apple apps, crash repeatedly, do not erase the iPhone as your first step. Make sure the phone is running the newest software it supports, restart it, and check that storage is not nearly full. If the problem continues after those checks, back up the iPhone and contact Apple Support for device-level troubleshooting.
If only one third-party app still crashes after an update and reinstall, the problem is more likely to be app-specific. Apple recommends contacting the developer; you can find App Support from the app’s App Store listing. Apple documents the process in its guide to contacting an app developer.
Apps that close suddenly on iOS 15 are usually crashing, not being intentionally shut down by iOS. Work from least disruptive to most disruptive: reopen the app, restart the iPhone, update the app, update iOS, check storage, and reinstall the affected app. A full erase and restore should be a last-resort device troubleshooting step, not the default fix for a single crashing app.
Fix the iMessage Is Signed Out error on iPhone by checking Apple Account sign-in, activation, connectivity, and settings—without erasing your messages.
Turn off your iPhone VPN in the app or Settings, confirm it disconnected, and stop automatic reconnections without deleting your account.
Learn how to encrypt your iPhone with a strong passcode, protect iCloud and computer backups, and secure your data if your phone is lost or stolen.
Learn how to clear Safari and Chrome cache on iPhone, manage app storage safely, and understand when clearing cached data actually helps.
Learn how to fight Gym Battles in Pokémon GO, pick effective attackers, use Charged Attacks and dodges, and claim a Gym after defeating its defenders.
Explore classic Cydia tweaks for jailbroken iPads, from SwipeSelection to Quasar, with compatibility warnings and modern alternatives.
Stop Apple Music signup prompts in the Music app. Learn where to find Show Apple Music on iOS and what turning it off does—and does not—change.
Set up a Shortcuts automation to text Mom when your iPhone battery gets low. Follow four steps, plus delivery checks and privacy tips.
Save posts on X in a few taps. Learn where to find the Bookmark button on iPhone, Android, and desktop, plus how to view, remove, and organize saved tweets.
Turn on AR mode in Pokémon GO during a wild encounter, find AR settings, and fix camera or device compatibility issues.