I cannot create a end portal in the game

I can't create a portal to the end on my own map

What I expected to happen was...:
Should have created a portal with the 12 decorative portal blocks and the 12 end eyes
What actually happened was...:
I was trying to create a portal to the end and kill the dragon, but I couldn't even place the portal structure correctly
Steps to Reproduce:
1. 
Fix it

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