- Go to a tower in the End, in Creative Mode, and have the Shift+F3 graph open.
- Destroy the bedrock below the crystal (being careful not to destroy the crystal).
You'll see the Fire block will become 1-sided (facing south), as it isn't resting on anything on its bottom (may or may not be relevant).
- You'll see the Fire block disappear and appear rapidly, causing the light to flicker rapidly.
The 'Tick' portion of the pie will increase, andyou will start to experience lag.
- Quit to the launcher, and in the Dev Console you will see a lot of
- "Can't Keep Up!"
- "Something's taking too long!"
You can make the lag go away by putting a block (doesn't have to be bedrock) back under the crystal.
Didn't occur before the 1.8 snapshots. The presence of the crystal prevented a Creative player from hitting it.