Java SecurityException: signer information does not match

Question

I recompiled my classes as usual, and suddenly got the following error message. Why? How can I fix it?

java.lang.SecurityException: class \"Chinese_English_D         


        

Answer 1

I had a similar exception:

java.lang.SecurityException: class "org.hamcrest.Matchers"'s signer information does not match signer information of other classes in the same package

The root problem was that I included the Hamcrest library twice. Once using Maven pom file. And I also added the JUnit 4 library (which also contains a Hamcrest library) to the project's build path. I simply had to remove JUnit from the build path and everything was fine.