Internal Error
GWT Designer encountered unexpected internal error.
This could be caused by a GWT Designer bug or by a misconfiguration issue, conflict, partial update, etc.
java.lang.IllegalArgumentException: Path must include project and resource name: /index.html
<welcome-file-list>
<welcome-file>/index.html</welcome-file>
</welcome-file-list>
I'm not sure why that would affect GWT Designer, but it did and that's how I got around it. Is this a bug or expected behavior?