Been outside again and had a fiddle. One bulb works fine, no errors at all, ive kept the car on for a few minutes. As soon as the other bulb is put in, error is flagged, and the error stays on whether the bulb is on or not.
Therefore one bulb is faulty and i know the other one works fine. So best contact the seller!
When you say one bulb was in, did you mean that one LED was in and one "normal" bulb? Because if I remember correctly, as long as one of your bulbs shows the expected resistance the error light will not come on.
I have not had good experiences with LEDs. They work for a while, then the resistor pops or something, and hello error light.