http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=22436649&linkID=9242019
We thank all our customers who identified these issues and reported them to us. These reports give us the opportunity to improve the product and provide you with the best solution in mechanical design. We also thank you for your continued business and for feedback regarding the content of this update release.
Respectfully,
Autodesk Inventor Product Team
This update fixes the Inventor 2013 issues when running on win8.1.
The 2012 fix for win8.1 should be released in another day or so.
Thanks,
Chris
Thank you for keeping us up to date with this release.
If this solved your issue please mark this posting "Accept as Solution".
Or if you like something that was said and it was helpful, Kudos are appreciated. Thanks!!!!