Jubula problems with "perform login" and login unassigned component names

Using Jubula standalone version 8.3.0.122 on Linux, I've run into a pair of related problems:

1. The "errors" section in the "Problems" view gave me two messages about Incomplete Test Data for node "Perform login". This would happen even with freshly created projects as soon as I did anything to modify the project, even changing the project description.
2. In object mapping mode there were three unassigned component names login_login_btn, login_password_txf and login_username_txf. This would happen even though I'd used no names even slightly similar, and would happen regardless of the AUT being used.