Index: src/main/java/common/javax/swing/plaf/basic/BasicTabbedPaneUI.java =================================================================== --- src/main/java/common/javax/swing/plaf/basic/BasicTabbedPaneUI.java (revision 509144) +++ src/main/java/common/javax/swing/plaf/basic/BasicTabbedPaneUI.java (working copy) @@ -142,6 +142,9 @@ } public void calculateLayoutInfo() { + if (tabPane == null) { + return; + } int tabCount = tabPane.getTabCount(); final Component selectedComponent = tabPane.getSelectedComponent(); if (selectedComponent != null) {