game crash

when i want to play mincraft i open the lancher and press the "play" button but when i get to the loding screen i lods and after a wile it crashes i can't tab out the game if i want to lissen to music or answer a call forme discord when i tab in to the game again it crashes. i have trid to uninstall it and install it again but it dosen't work so what is the problem and what can you do about it. thank you for your help.