On my server, that is being hosted via a hosting service, beacons are not working, I checked to make sure i had the correct format, and a placed the beacon correctly. The beam shows, but when I attempt to put any of the materials in to activate it, all the Buffs are still grayed out.

The beacon should have given me a choice of a buff and Regen:

The Beacon didn't give me a choice of A Buff and Regen, instead it remained grayed out. I tried re-logging, and replacing the beacon several times.

Steps to Reproduce:
1. Have an SMP server hosted.
2. On the server make a beacon (mine specifically was iron on the inside, diamonds on the out-most layer)
3. Try and activate it with any of the ingots, or gems.
4. Try to choose a Beacon Buff.