"Shell" command problem, "Cannot find vertex"

[nyrkkanm]

I recently created a part in Inventor 2020 and I am running into issues using shell to finish it off. The part is a nose cone that was created using surfaces and then sculpt. These steps resulted in a solid part, but I obviously need to hollow it out so it is able to fit around the vehicle. When I try to use "shell" and select the faces I want to remove, it returns an error saying "The attempted shell operation was unable to solve for a vertex". I have spent hours trying to figure a solution, but can't seem to figure it out. I have attached the file I am referencing. 

[Xun.Zhang]

Howdy @nyrkkanm I see that you are visiting as a new member to the Inventor Forum.
Welcome to the Autodesk Community!

Yes, this is impacted by the geometry that Multi-line vertex, let me investigate it a little bit and try to provide a solution then.

[nyrkkanm]

UPDATE: I attempted to solve this problem by simplifying a lot of the sketches and features, but I am getting the same error. I would appreciate any suggestions! I attached the new file below. 

[Xun.Zhang · Accepted solution]

Hello @nyrkkanm,

Have several tries, nut not able to do the shell as well as surface thicken.

This is a modeling error case that several curve contribute to a vertex, suggest to rebuild the surface a little bit.

Or try to create a hole in that vertex and you can complete shell a little bit as below enclosed file. 

[nyrkkanm]

Thanks for the help! So I am able to figure this out in the future, what was the function of the small hole up front?