@Anonymous
Welcome to the community..
This has popped up before in the past and nothing really solved it except for blah blah blah.. 
Here's what I would suggest if there's noting wrong with the model.. Can you confirm nothing is wrong with the model.
1. Exit Inventor
2. Select the Windows Start Button and type CMD in the search field but do not hit an enter.
3. When command prompt appears in the list, right mouse click on it and select Run as Admin.
4. In the command prompt navigate to C:\Program Files\Autodesk\Inventor 2017\Bin
5. Type Inventor.exe /install
6. Wait a few mins and then restart Inventor
Did that resolve the issue?
Mark Lancaster
& Autodesk Services MarketPlace Provider
Autodesk Inventor Certified Professional & not an Autodesk Employee
Likes is much appreciated if the information I have shared is helpful to you and/or others
Did this resolve your issue? Please accept it "As a Solution" so others may benefit from it.