If the player leaves the game and joins again, the chunks will on occasion not load properly. This leads to the whole world having render issues. With that said, the block is still technically there, its just invisible or black.
Linked issues
is duplicated by 9
MCPE-5844
Weird chunk errors cause lines to appear right in front of my cursor. Its really annoying and it seems like it can be resolved by breaking or placing a block in the missing chunk. The lines appear to lead you to the broken chunk.
Resolved
MCPE-5920
world glitch
Resolved
MCPE-5926
Textures disapear when breaking blocks.
Resolved
MCPE-5970
'Far' render distance does not render properly
Resolved
MCPE-6273
crashes
Resolved
4 more links
Cleaning up old issues, please reply if affecting 0.9.3