“App not installed”
Almost always an older copy still on the device with a mismatched signature, or not enough
free storage. Free up at least 200 MB, remove any 2J build you obtained from an
unofficial source, then install the fresh APK again.
“Parse error” when opening the file
The download did not finish, or the file was truncated in transit. Delete the partial file
from your Downloads folder, switch to a stable connection, and download it again from the
official lobby rather than resuming the broken transfer.
Play Protect blocks the install
Google Play Protect flags any app installed outside the Play Store as a matter of policy.
Choose Install anyway on the prompt. If you would rather not, the browser
web client gives you the identical slot library with nothing to install at all.
The install button does nothing
The unknown-sources permission has not been granted to the app you are opening the file
from. Note which app that is — your browser or your file manager — and enable
install access for that specific app in Settings, then try again.
Slots load slowly or freeze mid-spin
Turn on data saver mode in the app settings, close background apps, and clear the app cache
from Android’s Storage settings. If a specific slot is the only one that stutters, it
is likely still streaming its assets — give it one full load and it will be cached
from then on.
Cannot log in after an update
Force-close the app and reopen it so the session token refreshes. If the login screen still
rejects you, use the password reset flow with your registered mobile number. Never share a
one-time code with anyone, including anyone claiming to be support — genuine support
will never ask for it.