i have been playing osrs fine for a while but every time i try getting o RS3 it says
"your game session has now ended. to play again, please close your game client and wait 5 minutes before reloading the game."
i closed and reopened the client, i restarted my laptop, un-installed and re-installed the client upgraded my plug ins, i have done everything short of a factory restore.
i am perfectly content playing OSRS but i would like to access my RS3 as well...
I am not sure how it really works since I only play runescape 3. unless you have the other one up still. You also use ctrl alt delete to get task manager up then once you are there click more for it. Then search for anything tied to it, and end any of them on your computer. Hopefully this helps out.