Inventor Error. Cannot modify

[I LOVE ROBOTS!]

I don't remember how, but you can set up a multi-user project without using vault. at the top of the browser, click the arrow by model if you have the option of file status then select that. right click on the part and click resolve. then choose to steal checkout. if that doesn't work, try the same things in other projects. if all else fails, try a save copy as.