Confirm the new APK
Check version 3.2.6, package com.happymod.apk, published size, and SHA-256.
Update troubleshooting
Fix HappyMod update problems
An update can fail when the new APK does not match the installed package, signature, Android version, or available storage.
Four checks
Keep the package identity consistent.
Check Android and storage
Confirm Android 5.0 or later and enough space for the downloaded file and update process.
Identify signature conflicts
Android will not update an installed app with an APK signed by a different publisher identity.
Protect local data
Before removing an incompatible existing copy, understand whether uninstalling will erase local application data.
Do not force a mismatched updateA package or signature mismatch is an identity warning, not merely an inconvenience. Verify the source before deciding what to remove.