Can't move Widgets

when I go to widgets screens to move different widgets to and from the sidebar, I CAN’T DRAG THEM. When I move the cursor over the widget, I get the normal four-point cursor, but when I click the mouse to drag and move, nothing happens. It just HIGHLIGHTS the text as if I selecting the text to copy/paste. What’s going on? I switch to several different themes but still the same. HELP