java.lang.NullPointerException
        at org.openttdcoop.dev.grapes.PluginManager.invoke(PluginManager.java:211)
        at org.openttdcoop.dev.grapes.Grapes.onServerWelcome(Grapes.java:110)
        at org.openttd.network.NetworkClient.RECEIVE_ADMIN_PACKET_SERVER_WELCOME(NetworkClient.java:163)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.openttd.network.NetworkClient.delegatePacket(NetworkClient.java:75)
        at org.openttd.network.NetworkClient.receive(NetworkClient.java:61)
        at org.openttd.network.NetworkClient.run(NetworkClient.java:43)