| “App not installed” |
An older qr888 build is still on the phone and the signature clashes with the new file. |
Uninstall the old copy under Settings, then Apps. Your account lives on the server, so sign in again after the new install finishes. |
| “There was a problem parsing the package” |
The download stopped early, usually when the screen locked or the signal dropped. |
Delete qr888.apk from Downloads, reconnect to Wi-Fi, then download again and confirm the file reads 45 MB. |
| “Blocked by Play Protect” |
Play Protect flags any installer it cannot match to a Play Store listing. |
Tap More details, then Install anyway. If that option is missing, update Play Protect in the Play Store and retry. |
| Install button greyed out |
Install unknown apps is still off for whichever app you opened the file from. |
Go to Settings, Apps, Special app access and enable it for that specific browser or file manager, not for Android as a whole. |
| Installs, then closes on launch |
Android below 8.0, or too little free storage for the app to unpack. |
Check your Android version under About phone. Below 8.0, use the mobile browser; otherwise free up space and install once more. |