[MC-129868] Sea grass disappeared after upgrading to 18w20c

World from 18w16 was migrated to 18w20c and all sea foliage disappeared, leaving blank holes in the water

Linked issues

violine1101 2018-05-18T14:56:30Z

Duplicate of MC-129625, please search before creating a ticket.

**the search needs to be improved, I searched but didn't find anything (the other issue also)

violine1101 2018-05-18T15:37:38Z

You just need the right keywords; "sea grass upgrade" did it for me.