A recent AVG and Avast antivirus update is preventing DisplayFusion 9.9 from launching on some systems. If you're running into this issue, please update to the latest DisplayFusion 10.0 Beta.
If this is happening on the Windows taskbar, it does seem related to a Windows issue. This guide might help you out: https://www.techradar.com/news/windows-10-update-is-messing-with-the-taskbar-but-theres-an-easy-fix