This just happened recently, not sure what caused it. I recently uninstalled Adobe CS 6 (running out of space on root drive) but that shouldn't have affected Adobe CC? When I place the cursor over a setting slider (Exposure, Contrast etc) I can no longer drag the slider with the mouse. I can change settings by either entering a value in to the settings field or dragging the double ended arrow over the settings field. But it's much easier to adjust a setting by dragging its slider triangle.Everything else seems to work fine.
Thanks for any assistance on how to diagnose this!
Could you please check and let me know the exact version of Lightroom installed on your computer?
Also which operating system are you working on, Windows or MAC?
Did you try restarting Lightroom once?
You may try and reset the Lightroom preferences back to defaults and check if that helps.