Every time I open Sound Forge Pro 14 I have to go through the registration again, which is quite annoying. I have had this product since it came out and had to re-install it due to error code 59, that's when the problem started.
I recommend uninstall / reinstall, but .. using a third-party uninstaller that can remove left-over registry entries and other pertinent data the OS uninstall leaves behind, which is usually the root of recurring issues. Revo Uninstall and Geek Uninstall are two uninstallers that have pro and freeware versions. I have used Revo for many years w/o issues.
If the error reoccurs after using the above technique, contact Magix Customer Service which handles activation issues and such.