The customer was trying to renew the Gateway certificate (under Settings > All Settings > Notification Server > Certificate Management) used by the gateway for NS Reporting. After clicking on "Renew" button, the status just stayed in "Replacement in progress".
ITMS 8.6, 8.7
Status "replacing" must go away as soon as Internet Gateway (IG) can report its inventory to NS specifying a new certificate usage.
Go to the Internet Gateway:
If while trying to "Enable" Status Report in the Servers tab you get a message like this in the gateway logs:
Web exception occurred while getting status report certificate - The underlying connection was closed: An unexpected error occurred on a receive..
Check if the SMP server certificate is a valid one. You should be able to see a log entry just like the one here just below the one for the error message above:
Trying to enable status reporting for server 'https://<SMPSERVER>.example.com:4726'...
If you click on the link, it should try to reach the SMP Server and if there is a problem with the certificate, you can click to view the certificate properties and confirm if it is a valid one or not.
In case you need to remove an old SMP server certificate reference, try this (if removing and re-adding the SMP Server from the Servers tab in the Gateway UI doesn't do it):