I recently upgraded to Windows 8.1 and now when launching AutoCAD 2013 it asks me to reactivate the software. When I try it says I have an invalid serial number. I have entered all numbers correctly but it won' t activate license. It allows me to run software in evaluation mode and it works so I don't think Win 8.1 is the issue.
In short - whats wrong with my serial number and how do I activate as I now only have 7 days before evaluation mode runs out.
Help!!