GetUserByUserId throws exception

[jjstr8]

I'm trying to get the user name of a file that's checked out by another user.  When I call GetUserByUserId, it throws an Autodesk.Connectivity.WebServices.VaultServiceErrorException exception.  I'm assuming it's a credentials issue, since it works with my own user ID.  Hovering over the same file in the Vault browser tab in Inventor shows the user name, so I'm not sure couldn't get the same information in code.  Is there any way to make this work? 

[Markus.Koechl · Accepted solution]

This is something to be configured and requires no coding. Ensure that all users get read access to user/group definitions. The best practice to do this is to create a custom role that includes this and add this role to your main user group. 

[jjstr8]

@Markus.Koechl :  Thank you for the response.  Our IT department handles changes like that, and they're not very quick to respond.  I was hoping that someone knew the back-door method that the Vault add-in for Inventor uses.