What I expected to happen was the potion to work
What actually happened was...:
It started repeating with no effect
Steps to Reproduce:
1. Open Minecraft 15w51b
2. Enter Command /tp @e 1 1 1
3. Fly to stop falling
4. Try to drink a potion of night vision
That is because you are in the void. In the void, night vision does not work. Invalid.