GWT Compilation Error - IncompatibleClassChangeError

Question

When compiling the project, I get this obscure Exception

Looking for precompiled archives.  To disable, use -Dgwt.usearchives=false
Loading archived module: jar:         


        

Answer 1

I had same issue when I migrated gwt from 2.6.1 to 2.8. Actually this error caused by asm dependency. Some of your server dependency has internal dependency to asm. In my case its cglib. So I changed cglib to cglib-nodep and it worked :-)

   <dependency>
        <groupId>cglib</groupId>
        <artifactId>cglib-nodep</artifactId>
        <version>3.2.1</version>
    </dependency>

Answer 2

For me, I wasn't using gwt-servlet.jar and dependencies were referencing old versions of it. I added the latest (matching my gwt-user.jar) as a regular dependency and Maven then knew to only use the latest version. You can check your dependency tree with mvn dependency:tree -Dverbose