<p>I opened my Bitcoin Core program today on my Windows 7 PC via an external hard disk (1 TB) and I found the following <em>error</em>:</p>
<blockquote>
<p>MinGW Runtime Assertion<br />
Assertion Failed!</p>
<p>Program: E:\Blockchain\bitcoin-qt.ex<br />
File: chain.cpp, line 103</p>
<p>Expression: pindexWalk-&gt; pprev</p>
</blockquote>
<p>DEBUG LOG: <a href="http://pastebin.com/YNEuRAcv" rel="nofollow noreferrer">http://pastebin.com/YNEuRAcv</a></p>
<p>How do I fix this error without losing the blocks on my external hard disk which I have synchronized for months?</p>

CC BY-SA 4.0
2020-06-24T15:14:19.767Z
"For months"? Is your Internet connection very much constrained? If not, it won't take that long. If you can allocate >6GB of RAM or simply use the blocksdir configuration to migrate the intensively accessed chainstate subdirectory to SSD if you have one.
Chris Chen
CC BY-SA 4.0
2020-06-24T17:27:51.530Z
Hello Chris Chris, my internet connection is very slow. How do I fix Bitcoin Core MinGW Runtime Assertion Assertion Failed error?
Bit Coin
<bitcoin-core><blockchain><bitcoind><full-node><installation>
How Do I Fix This Error Without Loosing Stored Blocks On Pc?
Bit Coin
# How Do I Fix This Error Without Loosing Stored Blocks On Pc?

(Asked by: username_0 on 2020-06-24)

I opened my Bitcoin Core program today on my Windows 7 PC via an external hard disk (1 TB) and I found the following *error*:

> MinGW Runtime Assertion  
> Assertion Failed!
>
> Program: E:\Blockchain\bitcoin-qt.ex  
> File: chain.cpp, line 103
>
> Expression: pindexWalk-> pprev

DEBUG LOG: <http://pastebin.com/YNEuRAcv>

How do I fix this error without losing the blocks on my external hard disk which I have synchronized for months?

**Tags:** bitcoin-core, blockchain, bitcoind, full-node, installation

> **Comments:**
> **username_1**: "For months"? Is your Internet connection very much constrained? If not, it won't take that long. If you can allocate >6GB of RAM or simply use the blocksdir configuration to migrate the intensively accessed chainstate subdirectory to SSD if you have one.  
> **username_0**: Hello Chris Chris, my internet connection is very slow. How do I fix Bitcoin Core MinGW Runtime Assertion Assertion Failed error?  

---

## 0 answers

