> For the complete documentation index, see [llms.txt](https://docs.getupdraft.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getupdraft.com/android/unknown-sources-in-android.md). # Unknown sources in Android Enterprise applications, that are not installed via Google Play Store are blocked by Android Operating System per default. To install such enterprise applications you have to allow 'unknown sources' in the system settings of your android device to finish the installation of your application. To solve this issue follow these steps: 1. Navigate to your **Systemsettings** > **Security**. 2. Check the option **"Unknown sources"**. 3. Tap **OK** on the prompt message. 4. Select **"Trust"**. After that all enterprise applications can be installed without any issue.