This issue was found in, ExtJS 5.1 Commercial Release. I have also tested it out in most current nightly build as well. I have a main tab panel, and then a sub tab panel inside two tabs. If you visit the tab with a child tabpanel, and then go back to the other tab and disable then enable the Parent tab then the child tabpanel will become greyed out but still allow switching between. I have tested it and recreated it in a fiddle. Just click the button to toggle the second tab. It will also affect the css style of all buttons in the child tabpanel's current active tab.

I have tested this in Current Version:



  1. IE 8

  2. IE 9

  3. Firefox

  4. Chrome

  5. Chrome(Canary)

  6. Firefox(Dev addition)