I use many instances so I run into this bug quite often.
To mitigate this I do following things:
- Make sure to always stop the script before closing the client or system takes time to register that you have already closed a instance
- Restarting your PC or waiting about 10-15 minutes is enough time for system to realize the empty instance spot.
Basically its just a small bug that for a temporary time thinks you are running your max amount of instances. Takes about 10 or so minutes for system to refresh and get the exact number of instances you are running.
if the problem persists however, admin should be able to help.
PS: I'd personally love a force-close all instances button in our forum CP. would make life much easier