MooTools 1.5.1: Unable to get property 'prototype' of undefined or null reference

[Michael]

Hello,

Recently in IE 11.0.9600.17280 on Windows 7 I have been getting this error:

Unable to get property 'prototype' of undefined or null reference

The undefied or null reference is: Function

For this chunk of compressed code right near the top of the MooTools 1.5.1 Core:

Function.prototype.overloadSetter=function(usePlural){var self=this;return function(a,b){if(a==null)return this;if(usePlural||typeof a!='string'){for(var k in a)self.call(this,k,a[k]);if(enumerables)for(var i=enumerables.length;i--;){k=enumerables[i];if(a.hasOwnProperty(k))self.call(this,k,a[k]);}}else{self.call(this,a,b);}

return this;};}

See attached screenshot for details. Even if the debugger is closed it pops up prompting debugging. Not every time, maybe half the time.

Anyone else seen this? Any suggestions? I can't find anything on MSDN or elsewhere on the web regarding this issue. I thought Function was provided by the browser, so curious if there is some reason MooTools is being initialized or run even before IE initializes all its own objects.

Thanks,

Michael

[Chuck van der Linden]

um where does Watir factor into the question below?