<p>That block is not just orphaned, it is actually invalid. It exploits <a href="https://bitcoincore.org/en/2018/09/20/notice/" rel="noreferrer">CVE-2018-17144</a>. The only way to fix this error is to upgrade to <a href="https://bitcoincore.org/en/releases/0.16.3/" rel="noreferrer">Bitcoin Core 0.16.3</a> and begin a reindex following the upgrade.</p>

CC BY-SA 4.0
2018-09-28T19:20:35.797Z
exactly as described, problem solved
Lelo
CC BY-SA 4.0
2018-09-28T18:41:22.753Z
2018-09-28T18:41:22.753Z
Ava Chow
<p>I'm running bitcoin core version 0.16.2 on the <strong>Testnet</strong> and realized that it had stopped receving blocks after the <a href="https://testnet.blockchain.info/block-index/5355357/00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722" rel="nofollow noreferrer">1414433</a>.</p>

<p>I tried running bitcoin core with options <code>-reindex</code> and <code>-reindex-chainstate</code> without success.</p>

<p>I have delete all the data and restarted syncing again, but ended up in the same problem</p>

<p><em>PS: I am running in pruned mode</em></p>

<p>What I've encountered in the debug.log is:</p>

<pre><code>2018-09-28 16:43:38 UpdateTip: new best=00000000cb7df9801f21ccb4192844281d7da224d2213514050a8ad9a6d9ec7e height=1414432 version=0x20000000 log2_work=71.629388 tx=47735936 date='2018-09-27 03:27:30' progress=0.999747 cache=81.4MiB(531804txo)
2018-09-28 16:43:38 UpdateTip: new best=00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 height=1414433 version=0x20000000 log2_work=71.629388 tx=47735938 date='2018-09-27 04:03:19' progress=0.999751 cache=81.4MiB(531807txo)
2018-09-28 16:43:38 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 16:43:38 ERROR: ProcessNewBlock: ActivateBestChain failed
2018-09-28 16:43:39 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 16:43:39 ERROR: ProcessNewBlock: ActivateBestChain failed`

[...]

2018-09-28 16:56:17 connect() to 78.47.24.41:18333 failed after select(): Connection refused (111)
2018-09-28 16:56:44 connect() to [2001:0:5ef5:79fd:38b6:55d:3788:c387]:18333 failed: Network is unreachable (101)
2018-09-28 17:01:12 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 17:01:12 ERROR: ProcessNewBlock: ActivateBestChain failed
2018-09-28 17:09:07 connect() to [2003:ea:9bde:5600:1180:6df2:ba35:efd]:18333 failed: Network is unreachable (101)
2018-09-28 17:13:23 connect() to 45.55.161.7:18333 failed after select(): Connection refused (111)
2018-09-28 17:14:19 Potential stale tip detected, will try using extra outbound peer (last tip update: 1841 seconds ago)
2018-09-28 17:14:24 New outbound peer connected: version: 70013, blocks=1414565, peer=24
</code></pre>

<p>It seems to me that maybe block 1414433 is orphaned. How can I overcome this problem?</p>

<bitcoin-core><testnet>
Solving Bitcoin core's 'ActivateBestChain failed'
Lelo
# Solving Bitcoin core's 'ActivateBestChain failed'

(Asked by: username_0 on 2018-09-28)

I'm running bitcoin core version 0.16.2 on the **Testnet** and realized that it had stopped receving blocks after the [1414433](https://testnet.blockchain.info/block-index/5355357/00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722).

I tried running bitcoin core with options `-reindex` and `-reindex-chainstate` without success.

I have delete all the data and restarted syncing again, but ended up in the same problem

*PS: I am running in pruned mode*

What I've encountered in the debug.log is:

```
2018-09-28 16:43:38 UpdateTip: new best=00000000cb7df9801f21ccb4192844281d7da224d2213514050a8ad9a6d9ec7e height=1414432 version=0x20000000 log2_work=71.629388 tx=47735936 date='2018-09-27 03:27:30' progress=0.999747 cache=81.4MiB(531804txo)
2018-09-28 16:43:38 UpdateTip: new best=00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 height=1414433 version=0x20000000 log2_work=71.629388 tx=47735938 date='2018-09-27 04:03:19' progress=0.999751 cache=81.4MiB(531807txo)
2018-09-28 16:43:38 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 16:43:38 ERROR: ProcessNewBlock: ActivateBestChain failed
2018-09-28 16:43:39 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 16:43:39 ERROR: ProcessNewBlock: ActivateBestChain failed`

[...]

2018-09-28 16:56:17 connect() to 78.47.24.41:18333 failed after select(): Connection refused (111)
2018-09-28 16:56:44 connect() to [2001:0:5ef5:79fd:38b6:55d:3788:c387]:18333 failed: Network is unreachable (101)
2018-09-28 17:01:12 ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
2018-09-28 17:01:12 ERROR: ProcessNewBlock: ActivateBestChain failed
2018-09-28 17:09:07 connect() to [2003:ea:9bde:5600:1180:6df2:ba35:efd]:18333 failed: Network is unreachable (101)
2018-09-28 17:13:23 connect() to 45.55.161.7:18333 failed after select(): Connection refused (111)
2018-09-28 17:14:19 Potential stale tip detected, will try using extra outbound peer (last tip update: 1841 seconds ago)
2018-09-28 17:14:24 New outbound peer connected: version: 70013, blocks=1414565, peer=24

```

It seems to me that maybe block 1414433 is orphaned. How can I overcome this problem?

**Tags:** bitcoin-core, testnet


---

## 1 answers

### Answer by username_1 on 2018-09-28. Score: 7 | Accepted answer

That block is not just orphaned, it is actually invalid. It exploits [CVE-2018-17144](https://bitcoincore.org/en/2018/09/20/notice/). The only way to fix this error is to upgrade to [Bitcoin Core 0.16.3](https://bitcoincore.org/en/releases/0.16.3/) and begin a reindex following the upgrade.

> **Comments:**
> **username_0**: exactly as described, problem solved  

---

