Inventor.Exe Is Not Currently Registered And Did Not Correctly Re-Register On Start Up. This error can appear when opening Inventor after installing a new version on your computer while you still have an older version also installed. Inventor.Exe Is Not Currently Registered And Did Not Correctly Re-Register On Start Up.
This is probably due to a lack of administration rights. To solve this, right click the shortcut on the desktop and run the program as administrator, the first time. Once the program opens successfully, it will open successfully the following times you open the program without having to select the run as administrator option.