Sometimes nobody can play. Both open ends show numbers that are already used up or stuck in hands that can't reach them. This is a blocked game, often called a tranque or a trancado.
If every tile with those end numbers is gone or stuck in hands that can't play, the game is locked.
1Everyone flips their tiles face up.
2Each player (or team) adds up their own pips.
3The lowest count wins the hand.
In Pipside, tap End hand, then Blocked, then pick who had the fewest pips. Then tap the tiles that score.