If you receive this printout in your javascript console:
UberMenu initialized via window.load
This is not an error. It is a notice alerting you that UberMenu was loaded on the window load event rather than the document ready event.
This means that UberMenu is using a fallback event because something has prevented it from loading during the normal event.
By default, UberMenu will attempt to load on document ready. However, if there is a javascript error from another script on your site, it will prevent UberMenu’s javascript from being able to run on that event.
As a fallback, UberMenu will also try to load on the window load event, in case the document ready event failed to run. In this case, this message will print so that you will be aware of the issue. This allows UberMenu to run even though you have an issue with some other code on your site.
The solution is to resolve whatever javascript error you have on your site that is preventing UberMenu from being able to run on document ready.