I tried to find a solution but they were all for windows and/or complicated (for me). The solution for windows was basically opening the program as an administrator.
How to solve the problem on mac:
Right click runemate.jar
Select "open with"
Select the first option (Jar Launcher)
Now...
Hello!
So I was just casually doing Prime NMZ and I closed the client since an update was coming up to address the spellbook filter. But after the update, when I tried opening the bot again it keeps getting an 'IOException' error from the title. I've tried restarting, re-installing Runemate...