My friend cannot join my minecraft world

My friend cannot join my minecraft world. This has been happening for 4 months, what would happen on my friends side is that it gets stuck on "Building Terrain". On my side, the chunks would stop working, pick block wouldnt work, I cant open my inventory, and when I placed a block it wouldnt save. This is my 3rd bug report on this topic. This bug/glitch has realy dissapointed me and hurt my relationship with minecraft. Please fix this bug minecraft.