<p>I've successfully been using Bitcoin core for the past months, but since two weeks ago its synchronisation is always stopped at the exact same blockchain.
2 weeks later, sync is behind by 2 weeks. And the error message is still the same: "<em>No block source available</em>" and I have 0 active connections to Bitcoin network. </p>

<p>I have updated the client, and changed networks (I even tried from another country to tell you the truth).
I tried to type in "<em>rescan</em>" and "<em>reindex</em>".
EDIT : they worked, but sync is now stopped at another block...</p>

<p>Here is the end of the debug window after I did a rescan :</p>

<blockquote>
  <p>2016-12-25 21:36:12 Still rescanning. At block 440686. Progress=0.988020</p>
  
  <p>2016-12-25 21:36:53  rescan               821342ms</p>
  
  <p>2016-12-25 21:36:54 mapBlockIndex.size() = 441449</p>
  
  <p>2016-12-25 21:36:54 nBestHeight = 441448</p>
  
  <p>2016-12-25 21:36:54 setKeyPool.size() = 100</p>
  
  <p>2016-12-25 21:36:54 mapWallet.size() = 6</p>
  
  <p>2016-12-25 21:36:54 mapAddressBook.size() = 10</p>
  
  <p>2016-12-25 21:36:54 init message: Chargement des adresses...</p>
  
  <p>2016-12-25 21:36:54 torcontrol thread start</p>
  
  <p>2016-12-25 21:36:54 Loaded 60362 addresses from peers.dat  457ms</p>
  
  <p>2016-12-25 21:36:54 init message: Chargement de la liste d'interdiction...</p>
  
  <p>2016-12-25 21:36:54 init message: Starting network threads...</p>
  
  <p>2016-12-25 21:36:54 AddLocal([2a01:cb00:b1d:1d00:7f:42c7:afca:6f9a]:8333,1)</p>
  
  <p>2016-12-25 21:36:54 Discover: ASUS-PC - 2a01:cb00:b1d:1d00:7f:42c7:afca:6f9a</p>
  
  <p>2016-12-25 21:36:54 AddLocal([2a01:cb00:b1d:1d00:d8e0:fea5:2db:481f]:8333,1)</p>
  
  <p>2016-12-25 21:36:54 Discover: ASUS-PC - 2a01:cb00:b1d:1d00:d8e0:fea5:2db:481f</p>
  
  <p>2016-12-25 21:36:54 dnsseed thread start</p>
  
  <p>2016-12-25 21:36:54 net thread start</p>
  
  <p>2016-12-25 21:36:54 addcon thread start</p>
  
  <p>2016-12-25 21:36:54 opencon thread start</p>
  
  <p>2016-12-25 21:36:54 msghand thread start</p>
  
  <p>2016-12-25 21:36:54 init message: Chargement terminé</p>
  
  <p>2016-12-25 21:36:54 GUI: Platform customization: "windows"</p>
  
  <p>2016-12-25 21:36:54 GUI: PaymentServer::LoadRootCAs: Loaded  44  root 
  certificates</p>
  
  <p>2016-12-25 21:37:05 Loading addresses from DNS seeds (could take a while)</p>
  
  <p>2016-12-25 21:37:05 0 addresses found from DNS seeds</p>
  
  <p>2016-12-25 21:37:05 dnsseed thread exit</p>
</blockquote>

<p>Any leads ? </p>

CC BY-SA 3.0
2016-12-20T16:12:35.337Z
`-rescan` and `-reindex` are startup parameters. You add them to the startup command of Bitcoin Core, I don't think you can use them from the console.
Murch
CC BY-SA 3.0
2016-12-20T16:16:39.627Z
Possible duplicate of [What can I do when the blockchain synchronization is stuck at a specific block?](http://bitcoin.stackexchange.com/q/2979/5406)
Murch
CC BY-SA 3.0
2016-12-20T16:18:10.553Z
Possible duplicate of [How to resolve “no block source available”?](http://bitcoin.stackexchange.com/q/12952/5406)
Murch
CC BY-SA 3.0
2016-12-21T04:31:43.963Z
OK I'm sorry I'm going to need to ask you how to do "add them to the startup command" exactly... Thanks.
positive.citizen
CC BY-SA 3.0
2016-12-21T08:31:02.333Z
See this [description](http://bitcoin.stackexchange.com/a/45997/5406), you'll have to replace `-zapwallettxes` with `-reindex`.
Murch
CC BY-SA 3.0
2016-12-25T21:16:07.177Z
Hello,
Thanks for the help, but the -reindex command did not work. After a few days of running (reindex is slow...) the sync is now stopped **3** blocs after the one that it stopped before...
Any hints ?
positive.citizen
CC BY-SA 3.0
2016-12-26T00:37:51.633Z
Does the `debug.log` say anything else besides the previous error message?
Murch
CC BY-SA 3.0
2016-12-26T12:01:42.387Z
I added the end of the debug.log in my opening message. Thanks so much for your help. I have 300$ that will be lost if I don't manage to make thi work again...
positive.citizen
CC BY-SA 3.0
2016-12-29T13:19:14.160Z
Murch any insight ? Please I'm starting to lose any hope...
positive.citizen
CC BY-SA 3.0
2017-01-07T16:01:59.560Z
Is this a recent or old version of Bitcoin Core? What hardware are you running this on? Is it possible that your CPU is overheating? It is possible that either your disk or your computer is making mistakes in the calculation, and then a valid block comes out as invalid and the remainder of the blockchain thus cannot be synchronized. If you just want to get your money out see [Cannot access my bitcoins because my wallet is still synchronising. What can I do to spend them immediately?](http://bitcoin.stackexchange.com/q/6056/5406)
Murch
CC BY-SA 3.0
2017-01-07T16:11:01.240Z
Have you tried manually connecting to a specific node (e.g. found on bitcoin nodes)?
Murch
CC BY-SA 3.0
2017-01-07T16:23:16.820Z
I've just tried asking around for more suggestions: Are you using a VPN or Tor?
Murch
CC BY-SA 3.0
2017-01-09T18:39:59.420Z
Thank you for your help !
I am using Bitcoin Core v0.13.1. I am running this on my laptop (windows 7 flash disk), and my CPU is not overheating. I don't think hardware could be the issue here.
I will use your link to access my bitcoins, I will give up on repairing Bitcoin...
Best regards !
positive.citizen
<blockchain><synchronization>
Synchronisation stopped at one specific blockchain
positive.citizen
# Synchronisation stopped at one specific blockchain

(Asked by: username_0 on 2016-12-20)

I've successfully been using Bitcoin core for the past months, but since two weeks ago its synchronisation is always stopped at the exact same blockchain.
2 weeks later, sync is behind by 2 weeks. And the error message is still the same: "*No block source available*" and I have 0 active connections to Bitcoin network.

I have updated the client, and changed networks (I even tried from another country to tell you the truth).
I tried to type in "*rescan*" and "*reindex*".
EDIT : they worked, but sync is now stopped at another block...

Here is the end of the debug window after I did a rescan :

> 2016-12-25 21:36:12 Still rescanning. At block 440686. Progress=0.988020
>
> 2016-12-25 21:36:53 rescan 821342ms
>
> 2016-12-25 21:36:54 mapBlockIndex.size() = 441449
>
> 2016-12-25 21:36:54 nBestHeight = 441448
>
> 2016-12-25 21:36:54 setKeyPool.size() = 100
>
> 2016-12-25 21:36:54 mapWallet.size() = 6
>
> 2016-12-25 21:36:54 mapAddressBook.size() = 10
>
> 2016-12-25 21:36:54 init message: Chargement des adresses...
>
> 2016-12-25 21:36:54 torcontrol thread start
>
> 2016-12-25 21:36:54 Loaded 60362 addresses from peers.dat 457ms
>
> 2016-12-25 21:36:54 init message: Chargement de la liste d'interdiction...
>
> 2016-12-25 21:36:54 init message: Starting network threads...
>
> 2016-12-25 21:36:54 AddLocal([2a01:cb00:b1d:1d00:7f:42c7:afca:6f9a]:8333,1)
>
> 2016-12-25 21:36:54 Discover: ASUS-PC - 2a01:cb00:b1d:1d00:7f:42c7:afca:6f9a
>
> 2016-12-25 21:36:54 AddLocal([2a01:cb00:b1d:1d00:d8e0:fea5:2db:481f]:8333,1)
>
> 2016-12-25 21:36:54 Discover: ASUS-PC - 2a01:cb00:b1d:1d00:d8e0:fea5:2db:481f
>
> 2016-12-25 21:36:54 dnsseed thread start
>
> 2016-12-25 21:36:54 net thread start
>
> 2016-12-25 21:36:54 addcon thread start
>
> 2016-12-25 21:36:54 opencon thread start
>
> 2016-12-25 21:36:54 msghand thread start
>
> 2016-12-25 21:36:54 init message: Chargement terminé
>
> 2016-12-25 21:36:54 GUI: Platform customization: "windows"
>
> 2016-12-25 21:36:54 GUI: PaymentServer::LoadRootCAs: Loaded 44 root
> certificates
>
> 2016-12-25 21:37:05 Loading addresses from DNS seeds (could take a while)
>
> 2016-12-25 21:37:05 0 addresses found from DNS seeds
>
> 2016-12-25 21:37:05 dnsseed thread exit

Any leads ?

**Tags:** blockchain, synchronization

> **Comments:**
> **username_1**: `-rescan` and `-reindex` are startup parameters. You add them to the startup command of Bitcoin Core, I don't think you can use them from the console.  
> **username_1**: Possible duplicate of [What can I do when the blockchain synchronization is stuck at a specific block?](http://bitcoin.stackexchange.com/q/2979/5406)  
> **username_1**: Possible duplicate of [How to resolve “no block source available”?](http://bitcoin.stackexchange.com/q/12952/5406)  
> **username_0**: OK I'm sorry I'm going to need to ask you how to do "add them to the startup command" exactly... Thanks.  
> **username_1**: See this [description](http://bitcoin.stackexchange.com/a/45997/5406), you'll have to replace `-zapwallettxes` with `-reindex`.  
> **username_0**: Hello, Thanks for the help, but the -reindex command did not work. After a few days of running (reindex is slow...) the sync is now stopped **3** blocs after the one that it stopped before... Any hints ?  
> **username_1**: Does the `debug.log` say anything else besides the previous error message?  
> **username_0**: I added the end of the debug.log in my opening message. Thanks so much for your help. I have 300$ that will be lost if I don't manage to make thi work again...  
> **username_0**: username_1 any insight ? Please I'm starting to lose any hope...  
> **username_1**: Is this a recent or old version of Bitcoin Core? What hardware are you running this on? Is it possible that your CPU is overheating? It is possible that either your disk or your computer is making mistakes in the calculation, and then a valid block comes out as invalid and the remainder of the blockchain thus cannot be synchronized. If you just want to get your money out see [Cannot access my bitcoins because my wallet is still synchronising. What can I do to spend them immediately?](http://bitcoin.stackexchange.com/q/6056/5406)  
> **username_1**: Have you tried manually connecting to a specific node (e.g. found on bitcoin nodes)?  
> **username_1**: I've just tried asking around for more suggestions: Are you using a VPN or Tor?  
> **username_0**: Thank you for your help ! I am using Bitcoin Core v0.13.1. I am running this on my laptop (windows 7 flash disk), and my CPU is not overheating. I don't think hardware could be the issue here. I will use your link to access my bitcoins, I will give up on repairing Bitcoin... Best regards !  

---

## 0 answers

