TL;DR: Remove the system classloader JVM option from the application's Info.plist file. On macOS you may be getting an AgentLoadException when trying to start a bot with RuneMate. There has been a "fix" for this in another post, which however only worked because the author made a happy accident by getting the order of java arguments wrong. You will only be getting this issue when using the OSRS application. Right click on your OSRS application, and select "Show Package Contents" In the Contents directory you'll find a file called Info.plist Edit it with either Xcode or a text editor like TextEdit For Xcode, remove the JVMOptions entry as shown in the image below Using a text editor, remove the line saying <string>-Djava.system.class.loader=app.systemclassloader</string> Save the changes and start your OSRS application again. In case the application complains about "being damaged" now, simply remove and redownload the osrs application and try above steps again. Spoiler: Image: Xcode editor As a short, technical explanation, the OSRS application uses a custom classloader as system classloader, which is responsible for loading jar files (such as RuneMate's attach agent) during runtime. Jagex' custom classloader doesn't support this operation, which is why we have to remove the classloader from the JVM options. The Windows client does not include this classloader, making this only an issue for macOS. Feel free to ask question if you have problems, I've spent a lot of time figuring out the cause of the issue.