Block of glass with bug, instead of being transparent the glass turns black and I can not see anything. Skins are also black and I can not see the player with hiskin

The earth block is with a bug, the torch around it is black besides the leaves in the trees are black and the bush is also black one turn when it was for him to be transparent, the glass is also black when it was to be transparent .... I can not see the skins of the other players, they turn black in my game ..... Please solve that. Please. Instead of the blocks being transparent like the iron fence in the spans, it turns black ... Solve this please!
Thank you for your attention and solve this please!

Ass: Gabriela Cortez de Alencar Nick: babi_BR