java I'm making a game and I keep getting an error

java I'm making a game and I keep getting an error

I'm trying to make a loading and saving system so I can implement it into
the game, but I keep getting a error when trying to generate the level!
Please help me resolve this problem! If you do, Ill give you the link to
the pre alpha 3.0 (nothing yet thought).
Here is the error:
Exception in thread "main" java.lang.NullPointerException
at level.level.generatelevel(level.java:86)
at level.level.loadlevel(level.java:54)
at Window.Game.start(Game.java:121)
at Window.Game.main(Game.java:96)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at level.level.savelevel(level.java:70)
at Window.Game.stop(Game.java:114)
at Window.Game.windowClosing(Game.java:185)
at java.awt.Window.processWindowEvent(Unknown Source)
at javax.swing.JFrame.processWindowEvent(Unknown Source)
at java.awt.Window.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown
Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown
Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown
Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Here is the link to the code:
Click me for the code