So I'm seeing: -
AMQ5540: Application 'WebSphere MQ Client for Java' did not supply a user ID and password
AMQ5541: The failed authentication check was caused by the queue manager
CONNAUTH CHCKCLNT(REQDADM) configuration.
CONNAUTH CHCKCLNT(REQDADM) configuration.
from WebSphere MQ 8.0 when I attempt to connect from WebSphere Application Server (WAS) to a Queue Manager.
The solution ?
Read this IBM Technote: -
...
In MQ 8.0, a new function is introduced that requires MQ administrators using remote access to supply the userid and password. When the userid and password are not supplied or the password is incorrect, then the following error is displayed.
...
I chose to take the circumvention of setting the Queue Manager back to the pre-V8 days, with passing checking being optional: -
ALTER AUTHINFO(SYSTEM.DEFAULT.AUTHINFO.IDPWOS) AUTHTYPE(IDPWOS) CHCKCLNT(OPTIONAL)
Obviously, this goes AGAINST good practices around security, but, in this particular case, it's MY environment.
YOUR mileage WILL vary.