So, I had finally gathered enough gold for the Nether Reactor, so I activated it. I assumed that the reactor lasted forever, so I started making a door for it so I could exit and enter. However, when I broke the obsidian, the machine stopped, then all the obisdian started disappearing, and the core's surroundings turned into obsidian, with the core changing into a black and blue texture. When I hit it, to says incorrect pattern. What should I do?
It only lasts for 45 seconds. Your nether reactor core is worn out now, so if you want to activate it again you need 36 more golden ingots to make 4 more golden blocks. You can salvage your reactor though and reuse it by mining it out of the obsidian.