"Brug af synkron XMLHttpRequest i hovedtråden er forældet på grund af dens skadelige effekt på brugeroplevelsen. Læs mere på http://xhr.spec.whatwg.org/" I get it like a zillion times in the consol window of the inspector tool. Really - I am the one to decide how data gets from the browser to the database on the server. And it is not even correct. It is not outdated, and I am the one to decide, if it bad for user-experince. This "errormessage" is simply a pain in the ass, and absolutely useless. Only effect is corering up real errors... So how do I prevent it from popping up, every time a page is loaded, og ajax is used, or whatever makes it harass me?