I also want to combine btc from multiple wallet to single address, but I am getting strange error while sending from bitcoin core wallet. I have checked I have sufficient balance to pay fee. error i got is Signature must be zero for failed check multi sig operation. Have anyone idea what can be the issue and how to resolve it.
Signature(?) is invalid.
You sure your bitcoin core is updated, and you're not trying to broadcast a transaction that is incorrectly build / is spending outputs that are no longer valid? Or using conflicting versions(?)
If none of the above brings you any closer to a solution, maybe try to do a simple reinstall, or export your keys to electrum?
You suggested a valid point, I think my bitcoin core is outdated, let me try with updated version. Will I have to download whole blockchain again ? or old will work, actually it takes very long time to download entire blockchain.