Some apps won't open anymore

I've got a problem on an LG G4 with android 5.0 : Some apps can't be openned anymore. Facebook and and supercell games like 'clash of clans' for instance. Facebook close each time I try to open it and supercell games are locked on a black screen. That's why I didn't think it was the same issue but both happenned at the same time twice ... it has to be something they have in common... It happenned a first time and the only way I could unlock it was to factory reset the phone. It worked then for a few days but here I am with the same problem again and I'm looking for a way to fix this without factory reset each time ... I don't have any clue... maybe someone here can help ? Edit : I tried to uninstall facebook, reboot, reinstall. still crash at startup :(