Unknown error

I’ve recently gotten a new computer, and every server I’ve tried to go on, the clients always give me errors like this:

Idk if I have to download a certain version of java or something, I’m not the smartest when it comes to tech issues. Anyway. if someone can shed some light on what I have to do to start playin servers on this computer, I would love you.

Looks like a Java error, try updating to JDK/Jre 8, and retry with an IDE.