We have a lightning component that was working fine previously in IE11, but as we change our component attribute from aura to the lightning component like below: <lightning:buttonMenu aura:id="menu" onselect="{! c.handleSelect }" alternativeText="Show menu"> etc. After this change our component not working in IE11 and through the JS exception. [![enter image description here][1]][1] [1]: https://i.sstatic.net/yaRkd.png Our component starting giving the following JS Exception in IE11. Failure when getting component class definition [Expected ';'] This error only comes in IE11. The component works fine in all other major supported browsers like chrome, safari, firefox, edge.