Problem with mining a bitcoin fork 'bad-cb-height rejected by the'

[YRFCHIPOJNP]

There is a problem. We made a bitcoin fork with enlarged block size and sha254. All seem to work, coins are being mined through 'setgenerate true -1' in wallet.
But external mining through rpc or mining pool can't be set up - all blocks get rejected. Everything that was tried to fix it had no success.
Tried all versions of mining pools ucomp and its modified versions, node-merged-pool, miningcore, stratum. Tried to start either on linux or windows. All miners were used with them and every possible settings including directly without pool with 'nevermore miner'. Nothing works and it results the same - blocks were getting found and then rejected. What the problem with that?

Some of the errors took place from different miners and pools:
- Pool bitcoin5000 Thread 1 We thought a block was found but it was rejected by the daemon, share data:

2018-08-08 11:44:15 ERROR: AcceptBlock: bad-cb-height, block height mismatch in coinbase (code 16)
2018-08-08 11:44:15 ERROR: ProcessNewBlock: AcceptBlock FAILED

 submission failed with: bad-cb-height

[2018-08-15 00:36:27] accepted: 0/19 (diff 0.000), 686.20 MH/s booooo
[2018-08-15 00:36:27] reject reason: bad-cb-height

[r1s2g3]

Should should move the topic to the relevant section. I am bit confused whether this should go to the Bitcoin mining section as you are forking the bitcoin.

https://bitcointalk.org/index.php?board=14.0

or it should be moved to the Altcoin mining section because the coin created after the fork is Altcoin only

https://bitcointalk.org/index.php?board=160.0


Better you should move at Bitcoin mining first and let Moderator decide there.