It basically looks like some big structure would be high in the air, however there wasn't any.
Environment
Windows 10, java version 1.8.0_281
MC-215517
Dark stripes on the terrain
Resolved
Duplicate
0
This appears to be a duplicate of MC-214793, which hasn't yet been resolved. If you have any additional information to provide regarding this issue, feel free to comment on the parent ticket. If you feel that this issue is affecting you, feel free to vote for the duplicated ticket, to give Mojang a basic idea of how many people are impacted by the problem. Just to further inform you, this will not determine how quickly the bug gets handled or fixed.