Curtis,
I have copied this code to a vb.net project that I use for renaming inventor files through apprentice server. I am going to add the option to create a new inventor .ipj project in the new directory at the same time.
I am close but I cannot figure out how to fix this error with the designprojectmanger interface. Something is different between the iLogic editor and visual studio 2022. Do you have any clues on this?

' Set a reference to the DesignProjectManager object.
Dim oDesignProjectMgr As Inventor.DesignProjectManager
oDesignProjectMgr = Inventor.DesignProjectManager
Dim oProject As Inventor.DesignProject
' Create a new single user project
Dim sFullPath = newPath & newPrefix & ".ipj"
oProject = oDesignProjectMgr.DesignProjects.Add(Inventor.MultiUserModeEnum.kSingleUserMode, newPrefix, newPath)
Thank You!