On my Kubuntu 16.04, updgraded with actual packages, KRDC asks for password of "kdewallet", which always fails though correct password for kwallet is input. Starting passwordmanager explicitly (in german language "Passwortspeicher") the input window asks for "kdewallet" password for program "kwalletmanager5" and then input the same correct password succeeds. Effectively KRDC's use of kdewallet is broken.
On my Kubuntu 16.04, updgraded with actual packages, KRDC asks for password of "kdewallet", which always fails though correct password for kwallet is input. Starting passwordmanager explicitly (in german language "Passwortspeicher") the input window asks for "kdewallet" password for program "kwalletmanager5" and then input the same correct password succeeds. Effectively KRDC's use of kdewallet is broken.