I got this error when trying to compile. It doesn't include any of my code so this could be greenfoot.
Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space at java.awt.image.DataBufferInt.<init>(DataBufferInt.java:41) at java.awt.image.Raster.createPackedRaster(Raster.java:458) at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:1015) at java.awt.image.BufferedImage.<init>(BufferedImage.java:343) at apple.awt.CGraphicsConfig.createCompatibleImage(CGraphicsConfig.java:133) at greenfoot.util.GraphicsUtilities.toCompatibleTranslucentImage(GraphicsUtilities.java:285) at greenfoot.util.GraphicsUtilities.loadCompatibleTranslucentImage(GraphicsUtilities.java:227) at greenfoot.GreenfootImage.loadURL(GreenfootImage.java:260) at greenfoot.GreenfootImage.loadFile(GreenfootImage.java:287) at greenfoot.GreenfootImage.<init>(GreenfootImage.java:109) at greenfoot.util.GreenfootUtil.getGreenfootImage(GreenfootUtil.java:794) at greenfoot.core.ProjectProperties.getImage(ProjectProperties.java:269) at greenfoot.gui.classbrowser.role.ImageClassRole.getClassThatHasImage(ImageClassRole.java:98) at greenfoot.gui.classbrowser.role.ImageClassRole.getGreenfootImage(ImageClassRole.java:109) at greenfoot.gui.classbrowser.role.ImageClassRole.getImage(ImageClassRole.java:80) at greenfoot.gui.classbrowser.role.ImageClassRole.changeImage(ImageClassRole.java:156) at greenfoot.gui.classbrowser.role.ImageClassRole.buildUI(ImageClassRole.java:63) at greenfoot.gui.classbrowser.ClassView.update(ClassView.java:188) at greenfoot.gui.classbrowser.ClassView.updateView(ClassView.java:412) at greenfoot.core.GClass$2.run(GClass.java:600) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:677) at java.awt.EventQueue.access$000(EventQueue.java:85) at java.awt.EventQueue$1.run(EventQueue.java:638) at java.awt.EventQueue$1.run(EventQueue.java:636) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:647) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196) Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space at java.awt.image.DataBufferInt.<init>(DataBufferInt.java:41) at java.awt.image.Raster.createPackedRaster(Raster.java:458) at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:1015) at java.awt.image.BufferedImage.<init>(BufferedImage.java:343) at apple.awt.CGraphicsConfig.createCompatibleImage(CGraphicsConfig.java:133) at greenfoot.util.GraphicsUtilities.createCompatibleTranslucentImage(GraphicsUtilities.java:178) at greenfoot.GreenfootImage.<init>(GreenfootImage.java:141) at greenfoot.GreenfootImage.<init>(GreenfootImage.java:117) at greenfoot.util.GreenfootUtil.getGreenfootImage(GreenfootUtil.java:794) at greenfoot.core.ProjectProperties.getImage(ProjectProperties.java:269) at greenfoot.gui.classbrowser.role.ImageClassRole.getClassThatHasImage(ImageClassRole.java:98) at greenfoot.gui.classbrowser.role.ImageClassRole.getGreenfootImage(ImageClassRole.java:109) at greenfoot.gui.classbrowser.role.ImageClassRole.getImage(ImageClassRole.java:80) at greenfoot.gui.classbrowser.role.ImageClassRole.changeImage(ImageClassRole.java:156) at greenfoot.gui.classbrowser.role.ImageClassRole.buildUI(ImageClassRole.java:63) at greenfoot.gui.classbrowser.ClassView.update(ClassView.java:188) at greenfoot.gui.classbrowser.ClassView.updateView(ClassView.java:412) at greenfoot.core.GClass$2.run(GClass.java:600) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:677) at java.awt.EventQueue.access$000(EventQueue.java:85) at java.awt.EventQueue$1.run(EventQueue.java:638) at java.awt.EventQueue$1.run(EventQueue.java:636) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87) at java.awt.EventQueue.dispatchEvent(EventQueue.java:647) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)