Black and purple textures show on world Icon and world when clicked says world cannot be opened

This is related with my previous complaint, the world icon does not show anything besides the no texture design and I CAN'T open my world. Now my one question, WHY DO THESE BUGS KEEP AFFECTING WORLDS, I have lost BOTH my SURVIVAL AND REDSTONE WORLD to this issue and my previous complaint WHICH  NO ONE  has even taken the time to answer me, I am absolutely sick and TIRED of this, I  HAVE LOST the motivation to even play Minecraft, I have grown to be scared EVERY SINGLE TIME I log Oout of my world, I have created copies AND GUESS WHAT? they get affected TOO, look please just please fix this bug/error that is happening Mojang