Flutter and API connection problems

A Flutter mobile application may depend on a backend API for login, data, synchronization, notifications, or other application functions. Connection failures can occur in the mobile app, the device/network, the production domain, the API/backend server, authentication, or environment configuration.

Common symptoms #

You may see problems such as:

• the mobile app cannot connect to the server
• login fails only in the mobile app
• API requests time out
• unauthorized or authentication errors
• application data does not load
• the app works locally but not on a real device
• Android works but iOS does not, or vice versa
• the API works in a browser or test tool but not in the mobile app

Possible causes #

Broad causes may include:

• the app is configured for the wrong API or server environment
• the backend server or API is unavailable
• a DNS or production-domain problem
• an SSL/TLS certificate problem
• device or network connectivity issues
• an authentication or session problem
• an application configuration mismatch
• an API request or response error
• a mobile-platform networking or security restriction
• a stale mobile build or environment configuration
• incompatibility between the mobile client and the backend/API version in use

Safe diagnostic process #

1. Confirm that the backend/API is online and responding in the intended environment.
2. Verify that the mobile app is using the expected production or test environment according to the product documentation.
3. Confirm that the production domain and HTTPS certificate work correctly.
4. Test the device’s general internet and network connectivity.
5. Determine whether the issue affects Android only, iOS only, both platforms, or only one device/network.
6. Where appropriate, confirm that the same account or login works through another supported client or interface.
7. Record the exact application or API error message with secrets removed.
8. Check whether the problem began after a mobile-app update, backend update, server move, or configuration change.
9. Confirm that the current app build uses the intended environment documented for that product.
10. Review relevant backend or server logs privately, removing credentials, tokens, customer data, and other secrets.
11. Contact DotwebApps support if the issue remains unresolved.

For domain and certificate checks, see SSL and domain configuration. For authorization-related failures, see API authentication errors. For general backend hosting checks, see Server requirements.

Do not weaken transport or authentication security #

Do not disable TLS/certificate verification, expose authentication tokens, publish API keys, or make unverified source-code changes merely to make a connection succeed.

Do not assume a universal API base URL, Dart constant, Flutter package, Android or iOS configuration file, network-security rule, CORS fix, certificate-pinning setting, authentication code pattern, or build command. These details are product-specific.

If the backend hosting is the limitation #

If the backend hosting environment cannot provide capabilities required by the specific DotwebApps product, work with the hosting provider or choose another environment that meets the documented requirements. You can also explore DigiHostPro as an optional hosting choice, but compatibility must be checked against the specific product requirements. Changing hosting does not automatically fix a Flutter or API connection problem.

When contacting support, provide the product name, affected platform, device/network context where relevant, intended environment, sanitized error message, when the problem began, and steps already attempted. Never send passwords, API keys, OAuth secrets, private keys, database passwords, payment-card details, or full source code.