“Latest Version” on this guide means the current official Mast79 build, not a fixed number that stays the same for years. When a new build is released, the older one can fail to open.
Why 39 MB matters
The package is about 39 MB, which is small next to video apps. Android still needs a little free space to unpack it. If the install stops halfway, clear old downloads and try the official file again from the download page.
Older phones
Mainstream Android phones are supported. A phone that has not received a system update for a long time may not run the latest build. Updating Android, when the phone still offers it, is the first thing to try. If the app still closes, the device is outside the current range.
Do not keep two copies
Remove a build you did not install yourself before you add the official one. Then register or return through the login steps. Permission requests that go beyond a game are covered in the safety guide.