<p>Start the client with the <code>-reindex</code> command-line option.</p>

CC BY-SA 3.0
2013-06-30T22:36:07.110Z
2013-06-30T22:36:07.110Z
Pieter Wuille
<p>If you backup the wallet.dat file, then you should be able to remove everything else, and then Bitcoin-Qt will redownload the block chain.</p>

CC BY-SA 3.0
2013-06-30T22:36:38.987Z
This will work, but is overkill.
Pieter Wuille
CC BY-SA 3.0
2013-04-01T20:48:00.747Z
2013-04-01T20:48:00.747Z
lurf jurv
<p>I encountered a error whilst downloading Bitcoin-Qt on my Macbook version 10.6.8; it says "Failed to read block"<br>
How do I fix this error without losing the bitcoins currently in my wallet?<br>
Your assistance will be greatly appreciated.</p>

CC BY-SA 3.0
2013-03-28T01:31:15.973Z
You say that you are 'downloading Bitcoin-Qt'. Are you using a browser to download Bitcoin-Qt, or are you using Bitcoin-Qt to download the blockchain?
Nick ODell
CC BY-SA 3.0
2013-05-21T08:08:36.690Z
This question helped me with the same issue: http://bitcoin.stackexchange.com/questions/10295/bitcoin-qt-read-block-error
rMX
<bitcoin-core>
"Failed to read Block"
victor
# "Failed to read Block"

(Asked by: username_0 on 2013-03-28)

I encountered a error whilst downloading Bitcoin-Qt on my Macbook version 10.6.8; it says "Failed to read block"  
How do I fix this error without losing the bitcoins currently in my wallet?  
Your assistance will be greatly appreciated.

**Tags:** bitcoin-core

> **Comments:**
> **username_1**: You say that you are 'downloading Bitcoin-Qt'. Are you using a browser to download Bitcoin-Qt, or are you using Bitcoin-Qt to download the blockchain?  
> **username_2**: This question helped me with the same issue: http://bitcoin.stackexchange.com/questions/10295/bitcoin-qt-read-block-error  

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## 2 answers

### Answer by username_3 on 2013-06-30. Score: 2

Start the client with the `-reindex` command-line option.


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### Answer by username_4 on 2013-04-01. Score: 1

If you backup the wallet.dat file, then you should be able to remove everything else, and then Bitcoin-Qt will redownload the block chain.

> **Comments:**
> **username_3**: This will work, but is overkill.  

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