@mmcdara Thank you for taking the time to reply. I tried downloading the JRE and follow the instructions given on the linked page, but my Maple folder looks different, and I've not been able to follow the guide exactly as written.

As for the other hint, I'm not sure if I understand what you're refering to, to be quite frank; I'm not very tech-savy, so I don't really know, how to "run maple from a terminal window in online mode". 

The weird thing is, I can still type in maple, albeit I can't switch to text mode, press enter or backspace.