When I load a world/server that isn't a flat world the it freaks out and it rapidly changes what the block textures are but all the block's are still there, they're just changing textures.
MC-100218
World graphic bug
Resolved
Duplicate
0
Ben Kiley
(Unassigned)
Unconfirmed
Minecraft 1.9
Retrieved
Without further information like a screenshot (best with debug screen (F3) enabled), this is a duplicate of
MC-62958 - AMD graphics driver issue or
MC-32606 - Intel graphics driver issue.