This exception comes whenever someone installs 23AndMe SNP Converter.
Once we start seeing logs of this exception we cannot work further unless all temporary files and cache is cleared.
By this I mean end user needs to do:
1. Clearing Cache from IGB using the menu File/Preferences/Cache/Clear Cache
2. Resetting preferences to Default using the menu - File/Preferences/Other Options/Reset Preferences to default.

This issue freezes IGB.

Please see the logs:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.plaf.basic.BasicTabbedPaneUI.scrollableTabLayoutEnabled(Unknown Source)
at javax.swing.plaf.basic.BasicTabbedPaneUI.tabForCoordinate(Unknown Source)
at javax.swing.plaf.basic.BasicTabbedPaneUI.setRolloverTab(Unknown Source)
at javax.swing.plaf.basic.BasicTabbedPaneUI.access$2100(Unknown Source)
at javax.swing.plaf.basic.BasicTabbedPaneUI$Handler.mouseEntered(Unknown Source)
at com.affymetrix.igb.window.service.def.JTabbedTrayPane$2.mouseEntered(JTabbedTrayPane.java:158)
at java.awt.AWTEventMulticaster.mouseEntered(Unknown Source)
at java.awt.AWTEventMulticaster.mouseEntered(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEnterExit(Unknown Source)
at java.awt.LightweightDispatcher.trackMouseEnterExit(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(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$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.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)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException