itch.io

Sometimes that happens when there's not enough phone memory, so try to free up some of it. If it doesn't help, redownload the game.

If it's Android, I have a way. I don't know if it'll work for you but it works for me. 

If you tried to free up your storage but it isn't still working try this:

Go to your Settings then find Applications, then look for "Google Play Services" and "Package Installer", Clear data both of them and done. 

(I don't know if it's safe though, so...)