Java compile error, upgrade from 5.21.6 to 6.10.7

Hi All,

I am upgrading a V5 app to V7 and have successfully gone to 5.21.6 and am now stepping to 6.10.7. When I try to run locally I get the following java compile error, can anyone help resolve please?

Thanks,

Simon.

    [javac] C:\Scratch\Mendix\myClarks-V5 to V7\javasource\usersignupresetpassword\actions\LoginUser.java:38: error: method initializeSession in class Core cannot be applied to given types;
    [javac]         ISession session = Core.initializeSession(context, user, null, "");
    [javac]                                ^
    [javac]   required: IUser,String
    [javac]   found: IContext,IUser,<null>,String
    [javac]   reason: actual and formal argument lists differ in length