Support > Advanced Web Page Options > Maximum Wait

This field allows you to specify the maximum time (in seconds) you would like the browser to wait before a page is considered fully loaded. A page is considered fully loaded when the "page load" event is triggered. This may take several minutes for some pages. By specifying a value, the browser will stop waiting for the page load event value after this time.

This value is empty by default and should stay empty for almost of sites.