Facing error "Error: error parsing transient string: illegal base64 data at input byte 0 - proposal response: <nil>", while passing private data using -- transient flag

I used byfn network and deployed the latest private chaincode(which includes patch0 as suggested in the link https://jira.hyperledger.org/browse/FAB-10231)

while tring to invoke chaincode using the --transient flag getting the error "Error: error parsing transient string: illegal base64 data at input byte 0 - proposal response: <nil>"

Second case i just tried to add the "tMap, err := stub.GetTransient()" to my mycc chaincode and tried to extract as followed in the link https://jira.hyperledger.org/browse/FAB-10231.

i can able start the network while invoking the chaincode i am facing the same above mentioned error "Error: error parsing transient string: illegal base64 data at input byte 0 - proposal response: <nil>"

Can someone please guide how to use transient flag to post transaction with private data using --transient flag. If you are sharing sample chaincode and steps that will be so much helpful.

Thanks

Kumar M