Nether Reactor Activation

What I expected was to have the nether reactor to
Activate when I touched the nether reactor core.
I thought it was suppose to active the nether reactor.

What actually happened was that the nether reactor did not
Work ,and said "All player need to be close to the reactor" .
Even though I was within one block of the nether reactor.
I've saw a few reports on forums with the same
1. ...Collect the materials for a nether reactor
2. ...Build a nether reactor
3. ... Click the nether reactor core