When you see the "expired" status it usually means that the ePO server cannot reach these computers to deploy the agent.
But when you launch the task I suppose you're launching it through the web interface of your computer but no from the ePO server. First thing you should do is to check details of the deployment so you can see the exact problem with it
I tried launching it from both my computer and the eposerver both with the same results
What other details than the "Server Tesk Log Details" can I check?
following these logs the server doesn't even try to connect to the clients via the server tasks (Subtasks listing stays empty)