Blockchain stoped working the old wallets 8.4.1-8.4.3 are on block 2008003 things not going very well.
New wallet 11.2.1 ccminer fails on json_rpc_call.
To many problems again.
Two blockchains working in parallel the old wallets on block 2008003 at this moment and the new wallet on block 2008990.
Never liked unnecessary upgrade.
In later Bitcoin they changed the rpc interface. It now uses a new call "getblocktemplate"
https://en.bitcoin.it/wiki/GetblocktemplateHave you tried an updated miner? This one looks like it supports qubit and getblocktemplate:
https://github.com/Atrides/sph-sgminer