I created a new PlayN project from the 1.2 archetype using the command line given in the GettingStarted wiki page. I then imported this Maven Project into Eclipse, just bringing in the core, java, and html modules. If I right-click the Java project, I can choose my main class, and a window pops up with the background image shown. Note that I've done no real programming yet: I'm just using the default project configuration.
Next, I used GWT-compile through Eclipse on the HTML project, and I got no errors. When I run it as a Web application by using the provided URL (without removing the "?gwt.codesvr=127.0.0.1:9997" bit), the application runs fine aside the Eclipse Console gives a warning about being in Development Mode. (Specifically, "You are running in GWT Development Mode. For optimal performance you may want to use an alternative method.")
However, if I run the application the recommended way, by removing the gwt.codesvr parameter, then I keep getting a dialog box saying "GWT module 'testproject' may need to be (re)compiled."
After reading How do I run a maven/eclipse/GWT/playN app in production mode?, I tried doing mvn test -Ptest-html
and then pointing my browser at http://localhost:8080, but it gives the same error.
Am I doing something wrong?
(EDIT: I have no idea if this next point is significant or not, but I'll share it anyway. When I try to create a project from Eclipse, the newest PlayN archetype I can see is 1.0.3, even after telling Eclipse to update the Maven index. I'm running Eclipse Indigo.)