For some time I cannot close the activity tracker on my screen. Neither can I close displays such as backpack, quest list and worn equipment, which results in alot of open screen which I have to navigate in between to find the right one. Can anyone help how to fix this so that I can close these screens?
Assuming you are on desktop rather than mobile (I don't know about mobile):
Click the padlock icon on the top-right corner of the 'ribbon'. This is the bar of icons that you can open the various other interfaces from. Mine is at the bottom-right of the screen.
(It is different to the 'action bar' where you put attacking abilities etc. - the padlock icon on that does something else.)
The padlock should toggle between 'locked' and 'unlocked' interface, and when is unlocked all the interfaces should have red close buttons.