Obtain a Valid APK: Download the APK file from a trusted source, such as the official app store or a developer’s official website, ensuring it is compatible with your device. Use Proper Development Tools: If you are trying to create an APK from source code, you must use development tools like Android Studio to compile and sign the application correctly. Ensure Correct Renaming (If Applicable): In some rare cases, a developer might intentionally provide a valid APK with a .zip extension for easier sharing on forums. In that specific scenario, renaming it to .apk is the correct action. However, this only works if the internal structure is already a valid APK format. You can check the contents with a file manager to confirm if it contains folders like “res” and “META-INF”.