why can't i swipe to close down apps

[AC Question]

When i press and hold down the middle button apps that was open do not come up for me to swip a d close them.

 

[ManiacJoe]

Assuming you mean the square button for "recently used apps", when you tap (not hold) the button it will show you the recently used apps.
If you are not getting the list of apps, the list is already empty. This happens when you turn off or reboot the phone.

If that is not the case for you:
Which phone?
Which version of android?
Which carrier?
What exactly happens when you tap the "recent apps" button?