$fax_email_outbound_authorized_senders is only filled when fax_extension_advanced permission is set. However, the edit part doesn't verify that sizeof(NULL) creates a fatal error.
Fatal error: Uncaught TypeError: sizeof(): Argument #1 ($value) must be of type Countable|array, null given in /var/www/fusionpbx/app/fax/fax_edit.php:286 Stack trace: #0 {main} thrown in /var/www/fusionpbx/app/fax/fax_edit.php on line 286
This patch verifies that $fax_email_outbound_authorized_senders is an array before sizeof() evaluates it. You can now add faxes with the fax_extension_advanced disabled.
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