Sorry to hear you are having problems with Nessy. Here are some steps that fix the most common causes of problems our customers face.

We recommend working through these solutions in order and trying again after each to see if the issue is resolved.

Log out of Nessy (Classroom and Games) on all windows, before logging back in again. For security purposes, you can't be logged in as multiple users on one browser at the same time.
Your browser may be storing data from an older version of Nessy. See How do I clear my browsing history? for instructions depending on the browser you are using.
Another thing to check is that your browser is up to date. If useful, see How do I update my browser? for instructions catered to your browser type.
Check your connectivity/browser settings at help.nessy.com. For optimal performance, we recommend checking that your connection is stable, and not being used for other bandwidth-heavy platforms at the same time.
If multiple students are connecting at once, check our internet speed recommendations:
- 1-5 concurrent users: ≈ 10 - 25 Mbps
- 10-20 concurrent users: ≈ 50 Mbps
- 30+ concurrent users: ≈ 100 Mbps+
You may need to check that your network settings aren't blocking access to Nessy. For more information, see Network Connectivity Requirements. If you're using Nessy on a school or local authority's internet connection, you may wish to share this with your IT team.
Have you tried on another browser? You may have certain settings or extensions that are interfering with Nessy on your current browser. For more info, see Technical troubleshooting: browser settings

How do I clear my browsing history?