I noticed this has long since been fixed in the github’s Url.php.
Mvied, could you please post an update to the official wordpress plugin containing the newer function? Anyone running the debug bar or equivalent gets these notices on every page.
https://github.com/Mvied/Mvied/blob/master/Url.php line 484 has the updated fromString method that hasn’t yet made its way into the wordpress plugin. Using this will get rid of your errors