Hi Ariel, can you kindly try the following steps while you're connected to the Internet:
1. Open Little Math and click on the red "Get or Enter License Key" button at the upper right part of the window
2. In the small window that pops up, type your license key inside the "License Key" field, in the same way that it's written on the license key card or sticker included in your box set
3. Click on the "Activate" button and your key should get activated within a few seconds
In case your computer's Firewall or Anti-Virus is blocking Little Math from communicating with our server, do try disabling both Firewall and Anti-Virus temporarily.
Once you see a message saying your license key was successfully activated, please check if you can now access your Semester 1 and 2 lessons. You may also re-enable your Firewall and Anti-Virus.
If you still can't access your lessons or if you are still getting a "license is invalid" message,
please write to us at support[at]brillkids[dot]com and include the details below:
> Your Little Math license key
> Screenshot showing the error message or inactive buttons in Little Math
I hope this helps!
Cheers,
Kezia