If you purchase the Threema app from the Threema Shop, you may have to adjust your device’s security settings in order to install and/or update the app.
Android 14 and Newer
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If the dialog “Auto Blocker is on. To keep your phone safe, you can only install apps from authorized stores” is displayed after installing or updating Threema on a Samsung device, you have to deactivate the “Auto Blocker” feature:
in the system settings, tap on “Security and Privacy > Auto Blocker,” and deactivate the option
Android 8 and Newer
- If the dialog “For security reasons, you cannot install unknown apps from this source on your smartphone” is displayed after downloading the APK file from the Threema Shop, tap on “Settings,” and activate “Trust this source”
Android 7 and Older
- Activate “Unknown sources” in your device’s security settings
- It is recommended to deactivate “Unknown sources” once you have installed Threema
