Mining new litecoin based altcoin. Internal Server Error 500 I apologise if I put this question in wrong place.

I created new altcoin based on litecoin source code.
All looks ok, wallet and wallet-qt are compiled and running.
However when I trying to mine using cpuminer (minerd) I getting 500 error.

I put this settings to *coin.conf file:

rpcuser=miner1
rpcpassword=some_password_here
rpcallowip=127.0.0.1
rcpport=9332
server=1
gen=0


Command for minerd: 

minerd -a scrypt -o http://127.0.0.1:9332 -O miner1:some_password_here


Minerd output: 

[2017-06-29 10:38:02] 1 miner threads started, using 'scrypt' algorithm.
[2017-06-29 10:38:02] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2017-06-29 10:38:02] json_rpc_call failed, retry after 30 seconds


What I'm doing wrong? Is there something else I have to do to "launch" my new crypto currency?

Thank you for your help.
The problem is that the Litecoin I used 0.8.4.7, does not have embedded mining software.

I ended up with two solutions:


Create mining pool and then:


connect nodes to each other
run the miner on my mining pool

Compile and run (-gen=1 option) old Litecoin node then connect to th
e other nodes one.