I'm having the same issue as Boris, except my dependency tree shows that I'm using 3.1:
[INFO] +- com.google.gwt:gwt-user:jar:2.8.0-rc2:compile [INFO] | \- javax.servlet:javax.servlet-api:jar:3.1.0:provided (scope managed from compile) [INFO] \- com.google.gwt:gwt-dev:jar:2.8.0-rc2:compile [INFO] \- org.eclipse.jetty:apache-jsp:jar:9.2.14.v20151106:compile [INFO] +- org.eclipse.jetty:jetty-server:jar:9.2.14.v20151106:compile [INFO] | \- (javax.servlet:javax.servlet-api:jar:3.1.0:provided - scope managed from compile; omitted for duplicate) [INFO] \- (javax.servlet:javax.servlet-api:jar:3.1.0:provided - scope managed from compile; omitted for duplicate) The only place this is specified is in the parent pom: <dependencyManagement> <dependencies> <dependency> <groupId>com.google.gwt</groupId> <artifactId>gwt</artifactId> <version>2.8.0-rc2</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> </dependencies> </dependencyManagement> I get the exact same error that he posted when trying to run the codeserver. The only difference is that he's using *gwt-maven-plugin:1.0-rc-4* and I'm using *gwt-maven-plugin:1.0-rc-6* -- You received this message because you are subscribed to the Google Groups "GWT Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-web-toolkit+unsubscr...@googlegroups.com. To post to this group, send email to google-web-toolkit@googlegroups.com. Visit this group at https://groups.google.com/group/google-web-toolkit. For more options, visit https://groups.google.com/d/optout.