When you create a new hybrid mobile project (File -> New -> Hybrid Mobile...), on the first page of the dialog, you're shown an error at the top even though you haven't done anything yet.
This is ugly and violates http://www.eclipse.org/articles/Article-UI-Guidelines/Contents.html#Wizards Guideline 5.3.

Also, consider polishing the next page, too.

If I don't have an engine installed, I get the error Please select a Hybrid Mobile Engine. This is not very nice, but I'm not sure how to improve it - perhaps if there are no engines installed, have a different message? And if you have at least one engine, select the first one by default, so that we avoid unnecessary errors?