I was testing multisignature in multichain as given in your tutorial in the link below:
It was notice that sending of asset from regular to multisig address works perfectly.
However, when sending from a multisig address to another address (could be regular or multisig), it throws the following exception.
reason=message : Invalid public key: address,
Note : I am using java library https://github.com/SimplyUb/MultiChainJavaAPI