The problem is that what you are trying to do is a violation of YouTube's terms of service and in at least some cases very likely illegal. YouTube regularly blocks third-party downloaders because, quite simply, they are not allowed.
I think you will need to explain a bit more about this error3 and where you have seen it and what you was doing when you saw it! was it on a computer? a microwave? a phone? if it was on a computer was it a PC with microsoft windows? or an apple mac? Give some more info so people on here can help you a bit more.
its proven people can read minds lol. Im trying to convert an mp3 to a video clip to upload onto youtube so i can then post onto facebook. it keeps spitting out an error3 message every time i go to add it to my youtube account
its not 3rd party i dont think i dont even no what that means sorry if this seems dumb. Is it impossible to get a sound clip from my phone on to facebook then? because it should really help i got so far with it