Programs in netbeans do not terminate as they are done with execution but continue running on as "Running Tasks"

My programs in netbeans do not terminate as they are done with execution but continue running on as Running Tasks appearing at the right bottom corner of the netbeans window. Each time I re-run my same program a new thread is added to the 'Running Tasks' even when the code is done with execution.

Why is this caused ?

How can I rectify this ?

This is an extremely old question but I stumbled upon this having the same issue. Here is how I solved it:

Close NetBeans, delete the NetBeans folder from C:\Users\[your username]\AppData\Roaming\, then restart NetBeans. WARNING: this will delete any specific settings you've set (i.e. font size/style, etc) so beware of that before trying this

It seems one of the User Thread is running, post code to get the exact answer

Your programming is not exiting correctly. If it is a GUI make sure your main Frame is set to Exit on close, or that at least something is set to exit when the frame is closed.