Glitch with lightroom cc with mask tools and crop tools

Frustrating glitches since the latest update in lightroom cc. When using masking tools for radial filter ect, system hangs. No pins or overlays are showing, nor the area the tool it is affecting. So cant see the adjustment area. All the show pins and overlay boxes are checked. Then when I go to use the crop tool, it reverts to the previous photo, so have to keep closing the app and restarting. any help would be gratefully appreciated.