user56604: I was trying to clone the bitcoin's source code and run a completely new blockchain. I was successful in changing the initial parameters such as

pszTimestamp
nTime
nNounce

Generated a genesis block and replaced the hardcoded values of 

consensus.hashGenesisBlock
genesis.hashMerkleRoot

The above steps successfully generated the genesis block. But after then the bitcoin core is trying to load the checkpoints( I think so) from disk and results in error. 
2017-07-31 21:06:42 Bitcoin version v0.14.99.0-42307c4bf-dirty
2017-07-31 21:06:42 InitParameterInteraction: parameter interaction: -whitelistforcerelay=1 -> setting -whitelistrelay=1
2017-07-31 21:06:42 Assuming ancestors of block 0000000000000000003b9ce759c2a087d52abc4266f8f4ebd6d768b89defa50a have valid signatures.
2017-07-31 21:06:42 Using the 'standard' SHA256 implementation
2017-07-31 21:06:42 Using RdRand as an additional entropy source
2017-07-31 21:06:42 Default data directory /Users/username/Library/Application Support/Bitcoin
2017-07-31 21:06:42 Using data directory /Users/username/Library/Application Support/Bitcoin
2017-07-31 21:06:42 Using config file /Users/username/Library/Application Support/Bitcoin/bitcoin.conf
2017-07-31 21:06:42 Using at most 125 automatic connections (4864 file descriptors available)
2017-07-31 21:06:42 Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements
2017-07-31 21:06:42 Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements
2017-07-31 21:06:42 Using 2 threads for script verification
2017-07-31 21:06:42 scheduler thread start
2017-07-31 21:06:42 HTTP: creating work queue of depth 16
2017-07-31 21:06:42 No rpcpassword set - using random cookie authentication
2017-07-31 21:06:42 Generated RPC authentication cookie /Users/username/Library/Application Support/Bitcoin/.cookie
2017-07-31 21:06:42 HTTP: starting 4 worker threads
2017-07-31 21:06:42 init message: Verifying wallet(s)...
2017-07-31 21:06:42 Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2017-07-31 21:06:42 Using wallet wallet.dat
2017-07-31 21:06:42 CDBEnv::Open: LogDir=/Users/username/Library/Application Support/Bitcoin/database ErrorFile=/Users/username/Library/Application Support/Bitcoin/db.log
2017-07-31 21:06:42 Cache configuration:
2017-07-31 21:06:42 * Using 2.0MiB for block index database
2017-07-31 21:06:42 * Using 8.0MiB for chain state database
2017-07-31 21:06:42 * Using 440.0MiB for in-memory UTXO set (plus up to 286.1MiB of unused mempool space)
2017-07-31 21:06:42 init message: Loading block index...
2017-07-31 21:06:42 Opening LevelDB in /Users/username/Library/Application Support/Bitcoin/blocks/index
2017-07-31 21:06:42 Opened LevelDB successfully
2017-07-31 21:06:42 Using obfuscation key for /Users/username/Library/Application Support/Bitcoin/blocks/index: 0000000000000000
2017-07-31 21:06:42 Opening LevelDB in /Users/username/Library/Application Support/Bitcoin/chainstate
2017-07-31 21:06:42 Opened LevelDB successfully
2017-07-31 21:06:42 Using obfuscation key for /Users/username/Library/Application Support/Bitcoin/chainstate: 7bbd099730c6ddd0
2017-07-31 21:06:42 LoadBlockIndexDB: last block file = 0
2017-07-31 21:06:42 LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=0, size=0, heights=0...0, time=1970-01-01...1970-01-01)
2017-07-31 21:06:42 Checking all blk files are present...
2017-07-31 21:06:42 LoadBlockIndexDB: transaction index disabled
2017-07-31 21:06:42 Initializing databases...
2017-07-31 21:06:42 Pre-allocating up to position 0x1000000 in blk00000.dat
2017-07-31 21:06:42 init message: Verifying blocks...
2017-07-31 21:06:42  block index             208ms
2017-07-31 21:06:42 init message: Loading wallet...
2017-07-31 21:06:42 nFileVersion = 149900
2017-07-31 21:06:42 Keys: 2001 plaintext, 0 encrypted, 2001 w/ metadata, 2001 total
2017-07-31 21:06:42  wallet                  127ms
2017-07-31 21:06:42 setKeyPool.size() = 1999
2017-07-31 21:06:42 mapWallet.size() = 0
2017-07-31 21:06:42 mapAddressBook.size() = 1
2017-07-31 21:06:42 ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=0, nPos=8)
2017-07-31 21:06:42 *** Failed to read block
2017-07-31 21:06:42 Error: Error: A fatal internal error occurred, see debug.log for details

There was a thread explaining how to block the code from checking for checkpoints. https://bitcointalk.org/index.php?topic=225690.0 But the thread is outdated and the code has gone through a lot of changes.
I need some help solving the error and proceeding to instamine the first few block and hardcode them too in the code.

user2306: Try deleting the block files. That error signals that the proof of work on the loaded block is incorrect.

56604: <p>I was trying to clone the bitcoin's source code and run a completely new blockchain. I was successful in changing the initial parameters such as</p>

<ul>
<li>pszTimestamp</li>
<li>nTime</li>
<li>nNounce</li>
</ul>

<p>Generated a genesis block and replaced the hardcoded values of </p>

<ul>
<li>consensus.hashGenesisBlock</li>
<li>genesis.hashMerkleRoot</li>
</ul>

<p>The above steps successfully generated the genesis block. But after then the bitcoin core is trying to load the checkpoints( I think so) from disk and results in error. </p>

<pre><code>2017-07-31 21:06:42 Bitcoin version v0.14.99.0-42307c4bf-dirty
2017-07-31 21:06:42 InitParameterInteraction: parameter interaction: -whitelistforcerelay=1 -&gt; setting -whitelistrelay=1
2017-07-31 21:06:42 Assuming ancestors of block 0000000000000000003b9ce759c2a087d52abc4266f8f4ebd6d768b89defa50a have valid signatures.
2017-07-31 21:06:42 Using the 'standard' SHA256 implementation
2017-07-31 21:06:42 Using RdRand as an additional entropy source
2017-07-31 21:06:42 Default data directory /Users/username/Library/Application Support/Bitcoin
2017-07-31 21:06:42 Using data directory /Users/username/Library/Application Support/Bitcoin
2017-07-31 21:06:42 Using config file /Users/username/Library/Application Support/Bitcoin/bitcoin.conf
2017-07-31 21:06:42 Using at most 125 automatic connections (4864 file descriptors available)
2017-07-31 21:06:42 Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements
2017-07-31 21:06:42 Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements
2017-07-31 21:06:42 Using 2 threads for script verification
2017-07-31 21:06:42 scheduler thread start
2017-07-31 21:06:42 HTTP: creating work queue of depth 16
2017-07-31 21:06:42 No rpcpassword set - using random cookie authentication
2017-07-31 21:06:42 Generated RPC authentication cookie /Users/username/Library/Application Support/Bitcoin/.cookie
2017-07-31 21:06:42 HTTP: starting 4 worker threads
2017-07-31 21:06:42 init message: Verifying wallet(s)...
2017-07-31 21:06:42 Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2017-07-31 21:06:42 Using wallet wallet.dat
2017-07-31 21:06:42 CDBEnv::Open: LogDir=/Users/username/Library/Application Support/Bitcoin/database ErrorFile=/Users/username/Library/Application Support/Bitcoin/db.log
2017-07-31 21:06:42 Cache configuration:
2017-07-31 21:06:42 * Using 2.0MiB for block index database
2017-07-31 21:06:42 * Using 8.0MiB for chain state database
2017-07-31 21:06:42 * Using 440.0MiB for in-memory UTXO set (plus up to 286.1MiB of unused mempool space)
2017-07-31 21:06:42 init message: Loading block index...
2017-07-31 21:06:42 Opening LevelDB in /Users/username/Library/Application Support/Bitcoin/blocks/index
2017-07-31 21:06:42 Opened LevelDB successfully
2017-07-31 21:06:42 Using obfuscation key for /Users/username/Library/Application Support/Bitcoin/blocks/index: 0000000000000000
2017-07-31 21:06:42 Opening LevelDB in /Users/username/Library/Application Support/Bitcoin/chainstate
2017-07-31 21:06:42 Opened LevelDB successfully
2017-07-31 21:06:42 Using obfuscation key for /Users/username/Library/Application Support/Bitcoin/chainstate: 7bbd099730c6ddd0
2017-07-31 21:06:42 LoadBlockIndexDB: last block file = 0
2017-07-31 21:06:42 LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=0, size=0, heights=0...0, time=1970-01-01...1970-01-01)
2017-07-31 21:06:42 Checking all blk files are present...
2017-07-31 21:06:42 LoadBlockIndexDB: transaction index disabled
2017-07-31 21:06:42 Initializing databases...
2017-07-31 21:06:42 Pre-allocating up to position 0x1000000 in blk00000.dat
2017-07-31 21:06:42 init message: Verifying blocks...
2017-07-31 21:06:42  block index             208ms
2017-07-31 21:06:42 init message: Loading wallet...
2017-07-31 21:06:42 nFileVersion = 149900
2017-07-31 21:06:42 Keys: 2001 plaintext, 0 encrypted, 2001 w/ metadata, 2001 total
2017-07-31 21:06:42  wallet                  127ms
2017-07-31 21:06:42 setKeyPool.size() = 1999
2017-07-31 21:06:42 mapWallet.size() = 0
2017-07-31 21:06:42 mapAddressBook.size() = 1
2017-07-31 21:06:42 ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=0, nPos=8)
2017-07-31 21:06:42 *** Failed to read block
2017-07-31 21:06:42 Error: Error: A fatal internal error occurred, see debug.log for details
</code></pre>

<p>There was a thread explaining how to block the code from checking for checkpoints. <a href="https://bitcointalk.org/index.php?topic=225690.0" rel="nofollow noreferrer">https://bitcointalk.org/index.php?topic=225690.0</a> But the thread is outdated and the code has gone through a lot of changes.</p>

<p>I need some help solving the error and proceeding to instamine the first few block and hardcode them too in the code.</p>
 2306: <p>Try deleting the block files. That error signals that the proof of work on the loaded block is incorrect.</p>
