So basically most of the time I play on a crappy laptop that runs 1 chunk and still lags but when I go over to my PC to play it gives me an error message when I try to log in. I keep getting this error message. Anyone know how to fix this because every time I try to log in it doesn't let me back into my account on laptop or PC.

Sometimes, this will happen if you are a java player logging into Eagler, you get this message for some reason

Hi! If you have a Java account and are logging on via eagler then that just means that you need to type out the username you're using for eagler the exact same as the registered Java name (capitalization, etc)