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Cause: A host may not be able to configure global call-in for their meetings if the global call-in feature is disabled for their host account. 

Solution:

To verify the global call-in feature is enabled on the Webex site/host account:

1. Log in to your Webex Site Administration page. (Example: https://SITENAME.Webex.com/admin.php)
2. On the Site Administration home page, confirm there is a green check mark beside Global call-in:

• Note: If the desired option is not available on your site, contact Cisco Support.

3. In the left navigation bar, click on User Management > Edit User.
4. Enter your search criteria into the Username: or Email: field, then click the Search button.
5. Click the name of the account that needs to be modified.
6. Under Privileges > Telephony Privileges, check the Allow access to teleconference via global call-in numbers box.
7. Scroll to the bottom of the page, then click the Update button.