Ajax TruClient - Error in Load Mode

Hi,

My script is working fine in "Develop Mode" but its failing in "Load Mode".

In load mode, we are getting "Error -205177: exception while calling handlers in RuleEngine dispatch, ex=[Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE) [nsIWindowWatcher.activeWindow]"  nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)"  location: "JS frame :: chrome://truclientload/content/embed/lrUIRREJS.js :: <TOP_LEVEL> :: line 62"  data&colon; no], event=[Event type="dialog/confirm-closed" target="[object XrayWrapper [object Window]]"], handler=
function (e) {
    winWatcher.activeWindow = e.target;
}    [MsgId: MERR-205177]"

Its failing at a point where one pop up message is coming, which is a firefox pop up only.

Please find the attached sceenshot for reference.

Please suggest.

Regards,

Deepak