Collectible Card Game Headquarters

My opponent has the exact same Forge folder as me (copied directly from me before playing, including local cache folder). We were facing each other in a LAN game and it crashed suddenly at the beginning of my opponent's 4th turn. Here's the crash report:

Code: Select all

Forge Version:    1.5.50-r-1
Operating System: Windows 7 6.1 amd64
Java Version:     1.8.0_77 Oracle Corporation

java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
   at forge.net.GameProtocolHandler$1.run(GameProtocolHandler.java:59)
   at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
   at java.lang.reflect.Method.invoke(Unknown Source)
   at forge.net.GameProtocolHandler$1.run(GameProtocolHandler.java:55)
   ... 1 more
Caused by: java.lang.NullPointerException
   at forge.match.AbstractGuiGame.one(AbstractGuiGame.java:448)
   at forge.match.input.InputPayMana.activateManaAbility(InputPayMana.java:284)
   at forge.match.input.InputPayMana.activateManaAbility(InputPayMana.java:167)
   at forge.match.input.InputPayMana.onCardSelected(InputPayMana.java:82)
   at forge.match.input.InputBase.selectCard(InputBase.java:106)
   at forge.match.input.InputProxy.selectCard(InputProxy.java:145)
   at forge.player.PlayerControllerHuman.selectCard(PlayerControllerHuman.java:1462)
   ... 6 more