When running in compiled mode I get this dreaded GWT Module \'mymodule\' may need to be (re)compiled dialog message.
I\'ve compiled a list of the things that others
I had a similar problem. Doing mvn clean install on my GWT project got me a war file, which upon deploying in tomcat resulted in the same "GWT Module 'mymodule' may need to be (re)compiled" dialog message. I also did all the mentioned stuff in here without any success.
Doing mvn clean install -DskipTests=true did the job for me.
OR
Doing mvn clean install without invoking the generated test URL (sth. like this: http://)
The test phase obviously did overwrite my initially created *.nocache.js via some fancy development mode url, thus packaging me a wrong *.nocache.js in the end.