How to Enable or Disable 'Warn on Closing Window with Multiple Tabs' on Opera Browser?br br To Enable:-br br Step 1: Open Opera Browser.br br Step 2: Click on Menu Icon at the top left, and then click on 'settings.' br br Step 3: Scroll down at the very bottom, and then click on 'Advanced.' br br Step 4: Under 'user interface' section, click on toggle next to 'warn on closing window with multiple tabs' to enable it.br br br To Disable:br br Step 1: Follow till step 3 from above.br br Step 2: Under 'user interface' section, click on toggle next to 'warn on closing window with multiple tabs' to make it off.