Index: src/main/java/common/javax/swing/plaf/basic/BasicScrollBarUI.java =================================================================== --- src/main/java/common/javax/swing/plaf/basic/BasicScrollBarUI.java (revision 509144) +++ src/main/java/common/javax/swing/plaf/basic/BasicScrollBarUI.java (working copy) @@ -219,8 +219,10 @@ } } - scrollbar.revalidate(); - scrollbar.repaint(); + if (scrollbar != null) { + scrollbar.revalidate(); + scrollbar.repaint(); + } } }