Sorry, I should mention that I am "across2211" above. One account I use at work, the other at home.
All service packs / updates are installed. I did the command prompt procedure, and can't get past the loading screen of Inventor. After it disappears, so too does the process in task manager.
Can you check that you have full access rights to the %temp% folder ? Someone else had issues on win8.1 where they didn't have all the necessary rights there.
Remove all explicit permissions on %USERPROFILE%\AppData\Local\Temp and set to inherit permissions.
Or, go to Local Policies > Security Options, scroll to the bottom and set 'User Account Control: Run all administrators in Admin Approval Mode' to Disabled, then reboot.
Otherwise my only other suggestion is to uninstall/reinstall.
I just uninstalled/reinstalled. Same problem! I can't believe this is still happening. Have you come across anyone else with this same problem?
You could have a corrupt Profile. I will post a Windows Registry settings to repair the Windows Registry when I get back in the office next week.
Dont have any of those folders you are descriping there under %appadata%/autodesk/
at that location i have
But none labeled Inventor