Mouse pointer changes into a black box If your mouse cursor changes into a black box when moved over blank areas in a PDF document, use the solution below as a workaround. The problem is intermittent in nature, and reported for the May 2016 release of Acrobat Reader DC and Acrobat. Solution: Remove the icon cache file Adobe is working to resolve the issue. Meanwhile, follow these steps as a workaround: 1. Open the local appdata folder: C:\Users\USER_NAME\AppData\Local\Adobe\Acrobat\DC 2. Delete the following file in the local appdata folder: For Acrobat Reader DC: IconCacheRdr.dat For Acrobat DC: IconCacheAcro.dat 3. Relaunch Acrobat Reader DC or Acrobat DC.