Some time an error occurs during loading of some web page which is follow A Runtime Error has occurred. Do you wish to debug?
Or

Internet Explorer Script Error. An error has occurred in the script on line 1. Do you wish to continue running scripts on this page?

And you can make some modification in your Internet Explorer to avoid the error from displaying on the screen during loading of WebPages. Following is the procedure how to make changes open your Internet Explorer and click on the Tool and then on the option and click on the advanced tab and check the boxes which are next to Disable script debugging and remove the tick mark from the boxes with notification about every script error and at last click on the OK.