I was working at the simple BPM-beginner-tutorial "my name age" and was facing the following problem. Maybe some other beginner like me will face the same (kinda addlepated) problem, so I want to share my simple solution.
What so far I had done:
I created a process "MyNameAge" and two Web Dynpro components "FilMyNameAgeComp" and "DisplayMyNameAgeComp".
I added both to the public part "API".
I built the UI component (though I forgot on which point) successfully.
I referenced the WD-DC as a dependency to the process DC.
I created two tasks "FillMaNameAge" and "DisplayMyNameAge" in the process.
In the task editor I wanted to assign a user interface to the task. I pressed "Choose...", then selected "Online Technologies", in the next page selected "Web Dynpro Java), checked "Show supported components only" and pressed "Search".
No UI component was found. Though I didn't forget any step of the manual.
I found the problem was that I actually had altered something small in the WD components. Thus in the "Component Browser" on my Ui project there was a little * on it, which means "modyfied locally, rebuild needed".
Then I right-clicked on my UI-component and selected "Sync/Create Project" --> "Sync Used DCs" . After it was done the * vanished and I could choose the UI components in the task editor.
I hope this will help others, too.