NS_ERROR_FAILURE 0x80004005 when running TruClient FireFox script in HP PC

Hello,

When running TruClient script via Performance Center I receive a lot of these errors (see below). The script works fine in Vugen develop script mode and Vugen loadmode. The errors only occur on PC. The snapshot to which is referred is non existent: a log folder was created, but no png file inside.

Seems to me like somthing goes wrong in the browser. I am using HP PC 11.52 patch1

Loglevel  was set to disabled and snapshot on error.

Does anybody know what causes this?

Error -205177: exception while calling handlers in RuleEngine dispatch, ex=[Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIDOMCanvasRenderingContext2D.drawWindow]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: chrome://truclientrre/content/infra/UtilsFF.js :: <TOP_LEVEL> :: line 79"  data&colon; no], event=** 20.2: Click on Beëindig de sessie button ** failed - target object was not found., handler=
function onStepEnd(e) {
    if (e.retCode > 0) {
        genSnapshot(this, true);
    }
}       Snapshot Info [MSH 25 1]    [MsgId: MERR-205177]    [MsgId: MERR-205177]

Regards,

Peet