If you are having trouble with your ProtonMail mobile app, please try the following debugging steps to fix the app.
1. If you run into issues, try logging out and logging back in. Closing and re-opening the app may also work.
2. If issues persist, try clearing the local data cache. This can be down through the settings page as shown below.
3. As a last resort, you can uninstall and re-install the application.
4. If you continue to experience issues, please use the report bug feature in the application as described in this link: https://protonmail.com/support/knowledge-base/bug-report-form-within-ios-and-android/
5. If you cannot use the report bug feature, get in touch with us via this link https://protonmail.com/support-form. Please include the following information:
- iOS or Android
- Device Type (Nexus 5, iPhone 6, etc)
- Operating System Version (Android 5.1, iOS 8, etc)
- Application Version number (To find your version number, follow the instructions here: https://protonmail.com/support/knowledge-base/mobile-app-version-number-ios-and-android/).