This is a problem because you'll be unable to trigger portal activation after mistakenly placing the last ender eye while one of the middle 9 blocks is occupied by a non-air block.
MC-95910
Unable to activate end portal with non-air blocks in the middle
Resolved
Fixed
4
[Mod] redstonehelper
Confirmed
Minecraft 16w03a, Minecraft 1.9.4, Minecraft 16w20a
Minecraft 16w21a
Retrieved
Ah, I noticed this in creative, but the issue for survival players didn't register in my head, that is kinda a big deal if someone misplaces a block there and then their portal is kaput forever.