Disabiling 'X mark' in IE11 compatibility mode

Question

Iam working on GWT, tried to disable the 'x mark' which is appearing in IE11. By adding the following code in CSS. But could not disable 'x mark'.

::-ms-clear
{
    display: none;
    width : 0;
    height: 0;
}

I also tried the following tag in the html page.

 <meta http-equiv="X-UA-Compatible" content="IE=Edge"> 

I got the following info message. "Your *.gwt.xml module configuration prohibits the use of the current doucment rendering mode (document.compatMode=' CSS1Compat').
Modify your application's host HTML page doctype, or update your custom 'document.compatMode' configuration property settings".

Please suggest on how to disable this 'x mark'

P.S: Using IE11 browser in compatibility mode with document mode as 9.

Answer 1

::-ms-clear doesn't work in compatibility mode.