I recommend uninstall/reinstall again.. but use a third-party uninstaller like 'Revo Uninstall' which can remove left-over registry entries and other pertinent data the OS uninstall leaves behind, which is usually the root of recurring issues Geek Uninstall is another third-party uninstaller. Both have pro and freeware versions.
If you have other versions of Magix software installed, be careful do not remove any 'shared' plug-ins.
btw, welcome to the Magix Sound Forge users community @John-DeMarco .