Plugin Registration Form + Password Reset not workin w/ OF 4.0.1 ?

I finally made it and upgraded to the latest OF version 4.0.1 ;-)

Now the registration form (see here) and the password reset form (see here) ain't working anymore.

Error message as shown below:

java.lang.NullPointerException

at org.jivesoftware.openfire.admin.decorators.main_jsp._jspService(main_jsp.java:154)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)

at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)

at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)

at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)

at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:595)

at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)

at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)

at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)

at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)

at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)

at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)

at org.eclipse.jetty.server.Dispatcher.include(Dispatcher.java:115)

What went wrong? Are those Plugins unsupported? Worked with the version 3.9.3.