Navigator wont work all the time

[johnkeane440]

I am using a space navigator in Autodesk inventor.
It works great but very often when I open a part it wont work. I can have numerous parts open and it works in some but not in others. if I close down inventor as re-open it it will be fine fora while. whats causing this. Its very annoying.
Any help appreciated.
Thanks

[UtaSH]

Hi johnkeane440,

the navigation in Inventor was implemented by Autodesk natively in the application. Please contact the support team of Inventor for help with this issue.

Have you checked if the problem comes from your antivirus software? Maybe you have to create an exception for the driver (3dxservice.exe)?