App crashing or not loading

Also searched as: app not loading

Updated 11 October 2026

Short answer

A mobile app that "crashes" is one of two problems. Either the app itself hits an unhandled error and closes (a true crash), or it opens but can't load anything because its backend (the server and API it talks to) is down, slow or returning errors. Crash reports in the Play Console, App Store Connect, or a crash reporting tool show true crashes. Checking your API shows backend problems. If many users are affected at the same moment after nothing changed in the app, suspect the backend.

What's the problem

Users say the app closes on launch, freezes, shows a blank screen or a spinner, or "can't connect".

Why it happens

  • An unhandled error in the app, often in a new release or on a particular device or OS version.
  • The backend is down or returning errors. See backend down.
  • The API changed and the app version users have doesn't handle the new response.
  • Expired certificates or keys used by the app.
  • No connection on the user's device.
  • Out of memory on older devices.

How to fix it

  1. Check crash reports for the newest crashes and the stack trace.
  2. Check your backend is up and returning normal responses.
  3. Compare timing: did it start with a new app release (app problem) or with a backend change (backend problem)?
  4. For app crashes, fix the error and release an update, or roll back the release if your store allows it.
  5. For backend problems, fix the API, and keep old app versions working when the API changes.

What Preventionlabs checks

One click runs the full report on your domain. For this problem it shows whether your site loads, how fast, and where its redirects go; uptime checked every 5 minutes, with an email when the site goes down and when it is back. With Cloudflare connected, it also shows which pages returned server errors (5xx) to visitors, and when; recent deploys and account changes, with their times. It can't open your app or see crash reports from phones, so check those in your app's own dashboard.

Run your free report

Your first report is free, no card needed. Then A$50 a month, up to 10 domains. Read-only: it never changes anything.

Sources

  1. Android Developers: Crashesofficial docsAn Android app crashes whenever there's an unexpected exit caused by an unhandled exception or signal.
  2. MDN Web Docs: Window: fetch() methodreferenceThere is a network error (for example, because the device does not have connectivity).

Related

Backend down: server unreachable Check whether the backend answers at all: no response points to the server, DNS or firewall; an error code points to the app or its database. API not working Look at the status code and response body the API returns: 4xx means the request is wrong (login, data, limits); 5xx means the API's server failed. API timeout The API took longer than your app or a proxy was willing to wait. Find whether it's the network, the API being slow, or one slow operation inside it. "Failed to fetch" / fetch failed "Failed to fetch" means no usable response arrived: a network error, a blocked request (often CORS or mixed content), or a bad URL. The console says which.
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