If you are seeing messages from your Visual Studio (Express) complaining that your trial expired after 30 days, you need to sign in to your Visual Studio (and/or Microsoft Account).
OK. that was stating the obvious. Here is the frustrating part. You are trying to login but you cannot and you get the following error:
- Launch Inernet Explorer (v11 in my case)
- Click Tools > Internet Options > Security
- Click Internet
- Click Custom level
- Scroll all the way near the bottom
- Under Scripting > Active Scripting, click "Enable"
- click OK and close.
That should do it. Now you can sign in to your account, and activate your copy of VS Express.