I get this error a lot of times while building my GWT project. I have a get module imported from a jar which is downloaded from artifactory.
GWT Module com.model.MyCommonModel not found in project sources or resources. -> [Help 1]
So I usually resolve it by deleting the jar locally or by running
mvn dependency:purge-local-repository
And after this the jars are downloaded again and it starts to work without issues.
