Alg

I don't think it's a duplicate. The light is at "0".

Sorry for my english...

1. There is no light around

2. Solid block around the spawner ok

3. The spawner was ok before the Prerelease, I haven't modify anything.

Word created in october 2013 (I don't remenber what version at this date...)

Upgrade from 18w16a to Prerelease Pre2

(idem from 18w16a to Prerelease Pre1)

Yes I confirm the bug is NOT fixed in 18w22c : seagrass and item of seagrass always disappeared...

I think it' s important  : the items of seagrass in a chess disappeared too...