I am trying to update a meeting in my calendar which has others tagged as co-hosts. when I click on SEND, I get a notice from WebEx saying I need to have scheduling permission from the host to schedule meeting. I am the host of the meeting so should not need to give myself permission.
an easy fix might be to just login to your webex site and edit the meeting there rather than in outlook. it should update in your outlook once you do so. a not so fun workaround might be logging into your webex site and editing the meeting and removing the cohosts. see if the outlook invite is editable after that point.