Bug Instance still can't be created

I was having the same issue, until I completely uninstalled all forms of JRE / JDK (Java). It seems you might be running a newer version of Java like I was. Try completely clearing Java off your computer;

-Uninstall all Java version
-Uninstall all RuneScape clients
-Uninstall RuneMate
-Clear Jagex Cache
-Restart Computer
-Reinstall RuneScape Client
-Reinstall RuneMate (this automatically downloads and installs the client compatible Java version)

 

I had same problem and I think i fixed it by removing java path from environment variables. Check the post here Question - Runemate not working [ loading screen]

 

Is this for RS3?

 

It's for Runemate, when i started it or tried to add instance it just kept loading and loading.

 

I did reply on someone else issue like this. The way to get it to work is load all instance you want at once, if you load them one by one then you run into problems