Well on a Friday the list of reasons could be endless but on this particular Friday it was a man asleep at the wheel…
So to break this down quickly CM updates process via the SMS_DMP_Downloader Component so the perfect place to start would be the dmpdownloader.log file. As you can see below the log clearly states the reason for the issue. “The site is under offline mode”.
So if your scratching your head and wondering what that means its pretty simple. In order to get in console updates you have to have a Service Connection Point installed and set to online mode like the below screenshot. You can view the status of your SCP by opening the ConfigMgr Console and navigating to “\Administration\Overview\Site Configuration\Servers and Site System Roles” and viewing properties on the Service Connection Point.
Why would my site be in offline mode you might ask? Well one legitimate reason is if you support an offline environment and need to provide updates to it, if thats the case you need to set your site in offline mode prior to running the Service Connection Tool to upload your telemetry data. Once your done this process you should immediately turn the SCP back to online mode.
If this was not your issue you could check “D:\ConfigMgr\CMUStaging\ApplicabilityChecks” and see if your update shows in this folder if not check the “<CM Installation Directory>\CMUStaging\Manifest.xml” File to see if the update shows there. If it does not i would restart the SMS_DMP_Downloader component by going to “\Monitoring\Overview\System Status\Site Status” in the ConfigMgr Console and right clicking your site server and selecting Start –> Configuration Manager Service Manager. Find the Component you want to stop select query, stop, query , start.
At this point if you are still stuck id verify you indeed have an SCP installed and set to Online mode and i would engage your local firewall or proxy server team to do some captures and look for any dropped traffic. If this turns up nothing i would open a CSS ticket with Microsoft to investigate further.