Inventor Error. Cannot modify

[inventor_phild]

I agree that it sounds like a Vault related error. Even if you are not using Vault the suggestion that the project file is set to use Vault can cause this error.

To check, do the following,

1. Open the assembly in Inventor.
2. On the Launch panel, click Projects.
3. In the lower half of the dialog box, check the entry at Type. It should be single user. If it shows Vault, then that is the problem.
4. To resolve, create a new project file uisng Single User. Refer to this video.

http://students.autodesk.com/ama/ori...oject_File.swf