Ghostery was preventing Dropbox from syncing and also limiting installation of software from Autodesk (AutoCad/Revit). I did not have an opportunity to remedy the problem. I found myself almost daily quitting the Ghostery application when it started. The program should not limit daily workflow and operation of well-respected applications unless it is providing a specific alert as to why it should be doing so. Ultimately it was easier to uninstall than to troubleshoot.