Administration option in Bugzilla is not visible for an account administrator.

This issue can be caused when a same email address is used for both the user accounts in an Organization. If both these user accounts have 'user1@domain.com' as their email address, it will cause a permission synchronization glitch on the Bugzilla server. Admin has to change the email address on one of these accounts and file a support ticket to us, so we can do some necessary steps from back end to sync these changes on the server.