There is an teamwork. One element is reserved by another user. As he is offline, I could not edit the object by getting his request. Is there any solution for me to reserve the elements.
P.S.
Our roles are all Lead Architector. My computer is the server, which is managed by me.
I don't think it's possible - what we typically do is force the other user to sign out from the Teamwork menu.
To avoid this in the future - There's an option that I think ALL teamwork users should have checked under the Work Environment - Options>Work Environment>Comanpy Standards Schemes>Data Safety>Data Integrity> Release All when closing Teamwork Project with Send Changes.
If all your TW users have it checked and they've closed the file (without signing out) this should ensure that their data is saved and that no elements are reserved by offline users.