Welcome!

Theres no line that says: <string>-Djava.system.class.loader=app.systemclassloader</string> for me to remove

So I opened it and it now says Failed to bind to the game client because of an AgentLoadException

Hi so you download standalone and what do you do with it to make it work?

Having the same problem An internal error occurred (error code: Could not load JRE from The bundle “Java SE 8” couldn’t be loaded because its executable couldn’t be located..) I read to download the standalone version but it didn't help me either.