I have been trying to mining Steem for the last five days without success.
I had downloaded all the necessary file, include the latest blockchain.
But, I kept getting this error:
It turns out the problems was on the config file.
It needs to add a checkpoint.
checkpoint = [2931839 , "002cbc7f53cd19156412ac078ae8879114d92526"]
After that, start up Steemd.exe, it starts to sync... waited for a while.
Hurray, success! It is mining.
Have not found a block yet, sure I am excited to see my miner is mining. Yay!
Currently, I am using the latest window binaries from 
https://steemit.com/steem/@bitcube/steem-windows-wallet-and-miner-v0-12-0
Here is the list of the useful links.
Software release.
This is the newest release for next Tuesday's hardfork.
https://steemit.com/steemit/@hbhades/steem-release-in-5-days-will-update-payout-schedule
Helpful Mining Guides
For linux:
From 
https://steemit.com/steemhelp/@joseph/mining-steem-for-dummies
From@clayop
https://steemit.com/miner-category/@clayop/steem-miner-setup-in-ubuntu-15
For window:
From 
https://steemit.com/steem/@tuck-fheman/how-to-mine-steem-in-windows
From@pfunk
https://steemit.com/steem/@pfunk/guide-maximize-your-mining-hashrate-in-windows-by-mining-steem-in-a-vm
From
https://steemit.com/steem/@bitcube/steem-mining-in-microsoft-windows-a-builder-s-guide-part-1
https://steemit.com/steem/@bitcube/steem-mining-in-microsoft-windows-a-miner-s-guide-part-2
For Mac:
From 
https://steemit.com/steem/@trung81/mining-seem-on-a-mac
Blockchain to use:
This blockchain add checkpoint on the config file:
It is not formatted for notepad to edit. has to use notepad++ to edit.
http://steemitup.eu/
Happy Mining!
