A typical error you may face when your network connection is not established (yet) is event 8198:
Event ID: 8198
Description: License Activation (slui.exe) failed with the following error code:
In most cases, you can safely ignore this error. It is triggered when the License Activation process tries to activate a Microsoft product, but the network is not ready yet. In my case, event error 8198 popped up because my VPN connection was not up yet. A slow WIFI or disconnected network cable may also cause this error. In certain cases, your local firewall or (more likely) your company firewall may be blocking port 1688.
You may retry the activation manually. Therefore, open a Command Prompt and type “slmgr /ato”. This will immediately trigger a new activation attempt. Wait a few seconds, and the following popup will appear:
The eventlog now shows an Informational event, stating “Acquisition of End User License was successful., event 1013.