We have received few reports about the issue described below.
Launch Inventor that has not been activated yet on Windows 8.1 and Windows 7.
Accept privacy dialog.
When the try \ activate dialog is presented a crash occurs.
From our investigation we discovered that Microsoft update KB2977629 (Sept 9 2014) has contributed to this problem.
This hotfix is available in Windows 7 and 8.1.
The workaround for activating the product is to remove the hotfix.
Apparently the issue is impacting other Autodesk applications as well.