hi my minecraft has a bug, when i close it and turn off the computer, and turn on and go play, it has a gray screen, and i have to keep reinstalling it and losing all my maps, help me pls

O que eu esperava que acontecesse era ...:
thought that after having deleted the first time would solve the bug :/

O que realmente aconteceu foi ...:
but it didn't solve it and it keeps happening

Passos para reproduzir:
1. Coloque um guia passo a passo sobre como acionar o bug aqui
2. ...
3. ...