Hi There,
You have extremely limited information in your post so it is very difficult to assist.
In order for others to help you on this forum you will need to provide additional information, such as a high level overview of what has been deployed, versions, etc... and a more detailed description of the issue (for example, are users trying to schedule meetings with the @webex functionality and no Webex is being added to the meeting).
Alternatively, if the customer has paid for a Webex subscription and assuming they are up to date on their SMARTNet you can engage Cisco TAC.
