3 ms·

On 16 August, 2013 block 252,451 (0x0000000000000024b58eeb1134432f00497a6a860412996e7a260f47126eed07) was accepted by the main network, forking unpatched nodes

• kobeya 9y ago
  That was not a hard fork, and the recovery from it was not a hard fork. Notably there are still bitcoin nodes from before then synced to the network, although they require some care and attention to maintain. What happened was the behavior became probabilistic based on the state of the machine it was running on and the how much block history was being rewritten due to a recent reorg, etc. Usually if the node was restarted, it synced and ran just fine. The recovery didn't change the bitcoin consensus rules as seen by existing clients. There was just a temporary extra limit put in place (a soft-fork) to keep blocks small while the issue was sorted out, then lifted.