OpenPojo IncompatibleClassChangeError Exception

I'm using OpenPojo for validating getter and setter methods of a class. But while trying to validate my getter and setter methods I'm having following exception:

java.lang.IncompatibleClassChangeError: class com.openpojo.reflection.java.bytecode.asm.SubClassCreator has interface org.objectweb.asm.ClassVisitor as super class

My class:

public final class ClientToken implements RememberMeAuthenticationToken {

private static final long serialVersionUID = 3141878022445836151L;

private final String clientName;

private final Credentials credentials;

private String userId;

private boolean isRememberMe;

public ClientToken(final String clientName, final Credentials credentials) {
    this.clientName = clientName;
    this.credentials = credentials;
}

public void setUserId(final String userId) {
    this.userId = userId;
}

public void setRememberMe(boolean isRememberMe) {
    this.isRememberMe = isRememberMe;
}

public String getClientName() {
    return this.clientName;
}

public Object getCredentials() {
    return this.credentials;
}

public Object getPrincipal() {
    return this.userId;
}

@Override
public String toString() {
    return CommonHelper.toString(ClientToken.class, "clientName", this.clientName, "credentials", this.credentials,
            "userId", this.userId);
}

public boolean isRememberMe() {
    return isRememberMe;
}
}

Does anybody help me why this problem occurs.