<p>It looks like you did not change the stake modifier checkpoints which are found here: <a href="https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L40" rel="nofollow noreferrer">https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L40</a>. You will need to change these stake modifier checkpoints to match the stake modifiers of your checkpoint blocks.</p>

<p>If you don't want to check those checkpoints, you can just change this function: <a href="https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L508" rel="nofollow noreferrer">https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L508</a> to always return true. That should "fix" this problem that you are experiencing.</p>

CC BY-SA 3.0
2017-10-31T09:02:05.733Z
I did that. See my comment above.
m1k3y3
CC BY-SA 3.0
2017-10-31T10:10:57.507Z
a snippet of `checkpoints.cpp` [file](https://pastebin.com/Sm2UjJkN)
m1k3y3
CC BY-SA 3.0
2017-10-31T15:24:13.350Z
I didn't see your comment. I have updated my answer
Ava Chow
CC BY-SA 3.0
2017-10-31T16:07:42.617Z
since there are no blocks apart from genesis, where do I find one?
m1k3y3
CC BY-SA 3.0
2017-10-31T16:08:36.540Z
Just remove all of the modifiers for heights other than 0 and change the one for 0 to be whatever the stake modifier for your genesis block is.
Ava Chow
CC BY-SA 3.0
2017-10-31T16:54:18.857Z
I got the following output `AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600
ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000` can it be that modifier is `modifier=0x0000000000000000`? otherwise, please advise where should I search for it. Thanks.
m1k3y3
CC BY-SA 3.0
2017-10-31T17:39:53.257Z
I gave it a try as per your last update... still the same outcome...
m1k3y3
CC BY-SA 3.0
2017-10-31T18:23:23.763Z
I updated my answer again.
Ava Chow
CC BY-SA 3.0
2017-10-31T18:28:22.723Z
Thanks a ton. I will give it a try but what in case I want to use checkpoints later? Can those be safely enabled at the later stage ?
m1k3y3
CC BY-SA 3.0
2017-10-31T18:42:05.660Z
If you want to use checkpoints later then you will have to add back in that function and set the checkpoints map properly. I'm guessing that you are not setting it properly (stake modifier is probably wrong) so it isn't working. I don't know what the correct value for your genesis block is.
Ava Chow
CC BY-SA 3.0
2017-10-31T18:47:56.913Z
Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/67975/discussion-between-m1k3y3-and-andrew-chow).
m1k3y3
CC BY-SA 3.0
2017-10-30T19:12:45.507Z
2017-10-31T18:06:29.057Z
2017-10-31T18:06:29.057Z
Ava Chow
<p>You should find the correct modifier to use for block 0 by using getblock of your genesis hash</p>

<pre><code>getblock 00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
</code></pre>

CC BY-SA 3.0
2017-11-30T01:31:34.967Z
2017-11-30T01:31:34.967Z
watermelon
<p>What I have done so far: </p>

<ul>
<li>Generated new Genesis Block </li>
<li>Generated new MerkleRoot </li>
<li>Updated MerkleRoot </li>
<li>Updated Genesis block values</li>
<li>Commented out <a href="https://github.com/mammix2/boostcoin-core/blob/master/src/main.cpp#L2074-L2081" rel="nofollow noreferrer">these lines</a> </li>
<li>Compiled on CentOS 6  </li>
<li>Created <code>altcoin.conf</code>with </li>
</ul>

<blockquote>
<pre><code>rpcuser=someuser
rpcpassword=somepassword
</code></pre>
</blockquote>

<ul>
<li>lauched <code>./altcoin</code> </li>
</ul>

<p>at this point all seemed to be OK but... </p>

<ul>
<li><code>./altcoind getinfo</code> </li>
</ul>

<p>shows:</p>

<pre><code>{
    "version" : 60300,
    "protocolversion" : 60001,
    "walletversion" : 60000,
    "balance" : 0,
    "blocks" : 0,
    "connections" : 1,
    "proxy" : "",
    "difficulty" : 1.00000000,
    "testnet" : false,
    "keypoololdest" : 1400530204,
    "keypoolsize" : 104,
    "paytxfee" : 0.00000000,
    "mininput" : 0.00010000,
    "errors" : ""
}
</code></pre>

<ul>
<li>so I try to use internal miner to mine first block <code>./altcoind setgenerate true 8</code></li>
<li>while checking progress by <code>./altcoind getmininginfo</code> i got strange output</li>
</ul>

<p>which shows: </p>

<pre><code>{
    "blocks" : 0,
    "currentblocksize" : 0,
    "currentblocktx" : 0,
    "difficulty" : 1.00000000,
    "errors" : "",
    "generate" : true,
    "genproclimit" : 4,
    "hashespersec" : 0,
    "networkhashps" : 1.46543,
    "pooledtx" : 0,
    "testnet" : false
}
</code></pre>

<p>At this point, I've issues <code>./altcoind stop</code> and when I try to launch it again, <code>debug.log</code> shows: </p>

<pre><code>Altcoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600
ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000
 block index               1ms
Loading wallet...
nFileVersion = 60300
Error loading blkindex.dat
 wallet                  301ms
Done loading
mapBlockIndex.size() = 1
nBestHeight = -1
setKeyPool.size() = 101
mapWallet.size() = 0
mapAddressBook.size() = 1
</code></pre>

<ul>
<li>uncommented <a href="https://github.com/mammix2/boostcoin-core/blob/master/src/main.cpp#L2074-L2081" rel="nofollow noreferrer">these lines</a> </li>
<li>lauched <code>./altcoind</code></li>
</ul>

<p>and the same error over and over again... I am cracking my head already a while....</p>

<p>can one, please point me the right direction. thanks</p>

<p><strong>UPDATE1:</strong></p>

<ul>
<li>deleted all the content from <code>~/.altcoin/</code> except <code>altcoin.conf</code></li>
<li>launched <code>./altcoind</code> </li>
<li>issued <code>./altcoind setgenerate true 4</code></li>
</ul>

<p>at this point I figured out <code>./altcoind</code> starts up without complaining about <strong>stake modifier</strong> though everytime I want to restart I have to delete the contents of <code>~/.altcoin/</code> otherwise error pops up. </p>

<p>output of <code>debug.log</code>: </p>

<pre><code>AltCoin version v0.5.4.0-unk-beta ()
Default data directory /root/.thecoin
Loading addresses...
dbenv.open LogDir=/root/.altcoin/database ErrorFile=/root/.altcoin/db.log
Loaded 0 addresses
 addresses                30ms
Loading block index...
AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500     nModifierInterval=21600
00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
d8098e7eb449eed16c09fd7c97dec2acd1ec386ced36cf970a05c92fc2c0a05b
CBlock(hash=00000000324a1b505ecd, ver=1, hashPrevBlock=00000000000000000000, hashMerkleRoot=d8098e7eb4, nTime=1508926967, nBits=1d00ffff, nNonce=2600258680, vtx=1, vchBlockSig=)
  Coinbase(hash=d8098e7eb4, nTime=1508926967, ver=1, vin.size=1, vout.size=1, nLockTime=0)
    CTxIn(COutPoint(0000000000, -1), coinbase 04ffff001d020f274c4c205468652045636f6e6f6d697374202d2054686520626f79636f7474206f662051617461722069732068757274696e672069747320656e666f7263657273202d204f63742031392032303137)
    CTxOut(empty)
  vMerkleTree: d8098e7eb4
SetBestChain: new best=00000000324a1b505ecd  height=0  trust=1  moneysupply=0.00
 Upgrade Info: v0.5+ txdb initialization
ResetSyncCheckpoint: pending for sync-checkpoint ab0dad4b10d2370f009ed6df6effca1ba42f01d5070d6b30afeedf6463fbe7a2
ResetSyncCheckpoint: sync-checkpoint reset to 00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
 Upgrade Info: no txdb upgrade v0.3-&gt;v0.4 detected.
 Upgrade Info: v0.5+ no txdb upgrade detected.
 block index               4ms
Loading wallet...
nFileVersion = 60300
Performing wallet upgrade to 60000
keypool added key 1, size=1
keypool added key 2, size=2
keypool added key 3, size=3
...
...
keypool added key 101, size=101
keypool reserve 1
keypool keep 1
 wallet                  755ms
Done loading
mapBlockIndex.size() = 1
nBestHeight = 0
setKeyPool.size() = 100
mapWallet.size() = 0
mapAddressBook.size() = 1
Bound to port 11111
Added 1.1.1.90:11111 from 127.0.0.1: 0 tried, 1 new
Added 1.1.1.1:11111 from 127.0.0.1: 0 tried, 2 new
ThreadRPCServer started
ipv4 venet0: 127.0.0.1
ipv4 venet0:0: 2.2.2.62
addrLocalHost = 2.2.2.62:11111
IRC seeding/communication disabled
ThreadSocketHandler started
ThreadOpenAddedConnections started
trying connection 1.1.1.90:11111 lastseen=-391515.5hrs
ThreadOpenConnections started
ThreadMessageHandler started
ThreadStakeMinter started
CPUMiner started for proof-of-stake
ThreadDNSAddressSeed started
Loading addresses from DNS seeds (could take a while)
Added 9 addresses from 0:0:0:0:0:0:0:0: 0 tried, 11 new
connected 1.1.1.90:11111
Added time data, samples 2, offset +0 (+0 minutes)
Moving 1.1.1.90:11111 to tried
version message: version 60006, blocks=0
getblocks -1 to 00000000000000000000 limit 500
trying connection 1.1.1.9:11111 lastseen=-391515.5hrs
Added 13 addresses from 1.1.1.90: 1 tried, 23 new
GetMyExternalIP() received [2.2.2.62] 2.2.2.62:0
GetMyExternalIP() returned 2.2.2.62
connected 198.143.186.9:11111
Added 21 addresses from 0:0:0:0:0:0:0:0: 1 tried, 44 new
...
...
2017-10-31 13:15:58 UTC Flushing wallet.dat    
...
4 processors
Starting 4 BitcoinMiner threads
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
...
...
ThreadRPCServer method=getmininginfo
</code></pre>

<p>despite it is up and running and both nodes are connected to eachother, outputs of <code>./altcoind getinfo</code> and <code>./altcoind getmininginfo</code> are still the same. </p>

<p><strong>UPDATE 2</strong></p>

<ul>
<li>removed all hard checkpoints from <code>kernel.cpp</code> <a href="https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L40:L48" rel="nofollow noreferrer">link</a></li>
<li><p>added <code>( 0, 0x0000000000000000 )</code></p>

<p>// Hard checkpoints of stake modifiers to ensure they are deterministic
static std::map mapStakeModifierCheckpoints =
boost::assign::map_list_of
  ( 0, 0x0000000000000000 )
//    ( 0, 0x0e00670bu )
//    ( 19080, 0xad4e4d29u )
//    ( 30583, 0xdc7bf136u )
//    ( 99999, 0xf555cfd2u )
//    (219999, 0x91b7444du )
;</p></li>
<li><p>recompiled </p></li>
<li>removed all the contents of <code>~/.altcoin/</code> folder </li>
<li>added <code>altcoin.conf</code> </li>
<li>launched <code>./altcoind</code></li>
<li>issued <code>./altcoind getinfo</code> - output is still the same </li>
<li>issues <code>./altcoind setgenerate true 4</code> - </li>
<li><code>debug.log</code> output is the same as previously</li>
<li>issued <code>./altcoind stop</code> </li>
<li>launched <code>./altcoind</code> </li>
</ul>

<p>at this point I it failed again with the same error message </p>

<pre><code>AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600
ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000
</code></pre>

CC BY-SA 3.0
2017-10-27T14:18:21.967Z
I have also removed all checkpoints beside (0, genesisBlock) from `checkpoints.cpp` and recompile it again... still the same problem...
m1k3y3
CC BY-SA 3.0
2017-10-30T19:08:57.387Z
Is https://github.com/mammix2/boostcoin-core your source code or something you forked from?
Ava Chow
CC BY-SA 3.0
2017-10-31T09:01:37.967Z
I forked `peercoin master0.5` [link](https://github.com/peercoin/peercoin/tree/master-0.5) . Since it is for educational purposes, I did not submit code to GitHub or anywhere else, Let me know what you need and I will provide it via pastebin
m1k3y3
CC BY-SA 3.0
2017-10-31T14:07:21.417Z
I just have added **UPDATE 1** in the main block
m1k3y3
CC BY-SA 3.0
2017-10-31T18:15:20.830Z
It is not `altcoin` forum
Denis Leonov
CC BY-SA 3.0
2017-10-31T18:20:21.070Z
I have added **UPDATE 2** in the main block which covers some of the `kernel.cpp` changes advised by @AndrewChow
m1k3y3
<blockchain><proof-of-work><proof-of-stake><error><genesis-block>
altcoin debug.log shows ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0
m1k3y3
# altcoin debug.log shows ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0

(Asked by: username_0 on 2017-10-26)

What I have done so far:

* Generated new Genesis Block
* Generated new MerkleRoot
* Updated MerkleRoot
* Updated Genesis block values
* Commented out [these lines](https://github.com/mammix2/boostcoin-core/blob/master/src/main.cpp#L2074-L2081)
* Compiled on CentOS 6
* Created `altcoin.conf`with

> ```
> rpcuser=someuser
> rpcpassword=somepassword
>
> ```

* lauched `./altcoin`

at this point all seemed to be OK but...

* `./altcoind getinfo`

shows:

```
{
    "version" : 60300,
    "protocolversion" : 60001,
    "walletversion" : 60000,
    "balance" : 0,
    "blocks" : 0,
    "connections" : 1,
    "proxy" : "",
    "difficulty" : 1.00000000,
    "testnet" : false,
    "keypoololdest" : 1400530204,
    "keypoolsize" : 104,
    "paytxfee" : 0.00000000,
    "mininput" : 0.00010000,
    "errors" : ""
}

```

* so I try to use internal miner to mine first block `./altcoind setgenerate true 8`
* while checking progress by `./altcoind getmininginfo` i got strange output

which shows:

```
{
    "blocks" : 0,
    "currentblocksize" : 0,
    "currentblocktx" : 0,
    "difficulty" : 1.00000000,
    "errors" : "",
    "generate" : true,
    "genproclimit" : 4,
    "hashespersec" : 0,
    "networkhashps" : 1.46543,
    "pooledtx" : 0,
    "testnet" : false
}

```

At this point, I've issues `./altcoind stop` and when I try to launch it again, `debug.log` shows:

```
Altcoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600
ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000
 block index               1ms
Loading wallet...
nFileVersion = 60300
Error loading blkindex.dat
 wallet                  301ms
Done loading
mapBlockIndex.size() = 1
nBestHeight = -1
setKeyPool.size() = 101
mapWallet.size() = 0
mapAddressBook.size() = 1

```

* uncommented [these lines](https://github.com/mammix2/boostcoin-core/blob/master/src/main.cpp#L2074-L2081)
* lauched `./altcoind`

and the same error over and over again... I am cracking my head already a while....

can one, please point me the right direction. thanks

**UPDATE1:**

* deleted all the content from `~/.altcoin/` except `altcoin.conf`
* launched `./altcoind`
* issued `./altcoind setgenerate true 4`

at this point I figured out `./altcoind` starts up without complaining about **stake modifier** though everytime I want to restart I have to delete the contents of `~/.altcoin/` otherwise error pops up.

output of `debug.log`:

```
AltCoin version v0.5.4.0-unk-beta ()
Default data directory /root/.thecoin
Loading addresses...
dbenv.open LogDir=/root/.altcoin/database ErrorFile=/root/.altcoin/db.log
Loaded 0 addresses
 addresses                30ms
Loading block index...
AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500     nModifierInterval=21600
00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
d8098e7eb449eed16c09fd7c97dec2acd1ec386ced36cf970a05c92fc2c0a05b
CBlock(hash=00000000324a1b505ecd, ver=1, hashPrevBlock=00000000000000000000, hashMerkleRoot=d8098e7eb4, nTime=1508926967, nBits=1d00ffff, nNonce=2600258680, vtx=1, vchBlockSig=)
  Coinbase(hash=d8098e7eb4, nTime=1508926967, ver=1, vin.size=1, vout.size=1, nLockTime=0)
    CTxIn(COutPoint(0000000000, -1), coinbase 04ffff001d020f274c4c205468652045636f6e6f6d697374202d2054686520626f79636f7474206f662051617461722069732068757274696e672069747320656e666f7263657273202d204f63742031392032303137)
    CTxOut(empty)
  vMerkleTree: d8098e7eb4
SetBestChain: new best=00000000324a1b505ecd  height=0  trust=1  moneysupply=0.00
 Upgrade Info: v0.5+ txdb initialization
ResetSyncCheckpoint: pending for sync-checkpoint ab0dad4b10d2370f009ed6df6effca1ba42f01d5070d6b30afeedf6463fbe7a2
ResetSyncCheckpoint: sync-checkpoint reset to 00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6
 Upgrade Info: no txdb upgrade v0.3->v0.4 detected.
 Upgrade Info: v0.5+ no txdb upgrade detected.
 block index               4ms
Loading wallet...
nFileVersion = 60300
Performing wallet upgrade to 60000
keypool added key 1, size=1
keypool added key 2, size=2
keypool added key 3, size=3
...
...
keypool added key 101, size=101
keypool reserve 1
keypool keep 1
 wallet                  755ms
Done loading
mapBlockIndex.size() = 1
nBestHeight = 0
setKeyPool.size() = 100
mapWallet.size() = 0
mapAddressBook.size() = 1
Bound to port 11111
Added 1.1.1.90:11111 from 127.0.0.1: 0 tried, 1 new
Added 1.1.1.1:11111 from 127.0.0.1: 0 tried, 2 new
ThreadRPCServer started
ipv4 venet0: 127.0.0.1
ipv4 venet0:0: 2.2.2.62
addrLocalHost = 2.2.2.62:11111
IRC seeding/communication disabled
ThreadSocketHandler started
ThreadOpenAddedConnections started
trying connection 1.1.1.90:11111 lastseen=-391515.5hrs
ThreadOpenConnections started
ThreadMessageHandler started
ThreadStakeMinter started
CPUMiner started for proof-of-stake
ThreadDNSAddressSeed started
Loading addresses from DNS seeds (could take a while)
Added 9 addresses from 0:0:0:0:0:0:0:0: 0 tried, 11 new
connected 1.1.1.90:11111
Added time data, samples 2, offset +0 (+0 minutes)
Moving 1.1.1.90:11111 to tried
version message: version 60006, blocks=0
getblocks -1 to 00000000000000000000 limit 500
trying connection 1.1.1.9:11111 lastseen=-391515.5hrs
Added 13 addresses from 1.1.1.90: 1 tried, 23 new
GetMyExternalIP() received [2.2.2.62] 2.2.2.62:0
GetMyExternalIP() returned 2.2.2.62
connected 198.143.186.9:11111
Added 21 addresses from 0:0:0:0:0:0:0:0: 1 tried, 44 new
...
...
2017-10-31 13:15:58 UTC Flushing wallet.dat    
...
4 processors
Starting 4 BitcoinMiner threads
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
CPUMiner started for proof-of-work
...
...
ThreadRPCServer method=getmininginfo

```

despite it is up and running and both nodes are connected to eachother, outputs of `./altcoind getinfo` and `./altcoind getmininginfo` are still the same.

**UPDATE 2**

* removed all hard checkpoints from `kernel.cpp` [link](https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L40:L48)
* added `( 0, 0x0000000000000000 )`

  // Hard checkpoints of stake modifiers to ensure they are deterministic
  static std::map mapStakeModifierCheckpoints =
  boost::assign::map\_list\_of
  ( 0, 0x0000000000000000 )
  // ( 0, 0x0e00670bu )
  // ( 19080, 0xad4e4d29u )
  // ( 30583, 0xdc7bf136u )
  // ( 99999, 0xf555cfd2u )
  // (219999, 0x91b7444du )
  ;
* recompiled
* removed all the contents of `~/.altcoin/` folder
* added `altcoin.conf`
* launched `./altcoind`
* issued `./altcoind getinfo` - output is still the same
* issues `./altcoind setgenerate true 4` -
* `debug.log` output is the same as previously
* issued `./altcoind stop`
* launched `./altcoind`

at this point I it failed again with the same error message

```
AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600
ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000

```

**Tags:** blockchain, proof-of-work, proof-of-stake, error, genesis-block

> **Comments:**
> **username_0**: I have also removed all checkpoints beside (0, genesisBlock) from `checkpoints.cpp` and recompile it again... still the same problem...  
> **username_1**: Is https://github.com/mammix2/boostcoin-core your source code or something you forked from?  
> **username_0**: I forked `peercoin master0.5` [link](https://github.com/peercoin/peercoin/tree/master-0.5) . Since it is for educational purposes, I did not submit code to GitHub or anywhere else, Let me know what you need and I will provide it via pastebin  
> **username_0**: I just have added **UPDATE 1** in the main block  
> **username_2**: It is not `altcoin` forum  
> **username_0**: I have added **UPDATE 2** in the main block which covers some of the `kernel.cpp` changes advised by @AndrewChow  

---

## 2 answers

### Answer by username_1 on 2017-10-30. Score: 0 | Accepted answer

It looks like you did not change the stake modifier checkpoints which are found here: <https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L40>. You will need to change these stake modifier checkpoints to match the stake modifiers of your checkpoint blocks.

If you don't want to check those checkpoints, you can just change this function: <https://github.com/peercoin/peercoin/blob/master-0.5/src/kernel.cpp#L508> to always return true. That should "fix" this problem that you are experiencing.

> **Comments:**
> **username_0**: I did that. See my comment above.  
> **username_0**: a snippet of `checkpoints.cpp` [file](https://pastebin.com/Sm2UjJkN)  
> **username_1**: I didn't see your comment. I have updated my answer  
> **username_0**: since there are no blocks apart from genesis, where do I find one?  
> **username_1**: Just remove all of the modifiers for heights other than 0 and change the one for 0 to be whatever the stake modifier for your genesis block is.  
> **username_0**: I got the following output `AltCoin Network: genesis=0x00000000324a1b505ecd nBitsLimit=0x1d00ffff nBitsInitial=0x1c00ffff nStakeMinAge=604800 nCoinbaseMaturity=500 nModifierInterval=21600 ERROR: CTxDB::LoadBlockIndex() : Failed stake modifier checkpoint height=0, modifier=0x0000000000000000` can it be that modifier is `modifier=0x0000000000000000`? otherwise, please advise where should I search for it. Thanks.  
> **username_0**: I gave it a try as per your last update... still the same outcome...  
> **username_1**: I updated my answer again.  
> **username_0**: Thanks a ton. I will give it a try but what in case I want to use checkpoints later? Can those be safely enabled at the later stage ?  
> **username_1**: If you want to use checkpoints later then you will have to add back in that function and set the checkpoints map properly. I'm guessing that you are not setting it properly (stake modifier is probably wrong) so it isn't working. I don't know what the correct value for your genesis block is.  
> **username_0**: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/67975/discussion-between-username_0-and-andrew-username_1).  

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### Answer by username_3 on 2017-11-30. Score: 0

You should find the correct modifier to use for block 0 by using getblock of your genesis hash

```
getblock 00000000324a1b505ecd77b793658f4fa6cd386653fdabd7d1c66907177174d6

```


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