How to reproduce:

1. Have at least 2 tablets
2. Go to the upgrades screen.
3. Buy an Upgrade
4. If you move to another upgrade, you will have to do step 3 again.
5. Hit the Reset Button
6. Hit the Sell Button.

Expected Result:

Upon reset, the sell button should be changing into buy button.

Actual Result:

Upon reset, the sell button stays visible, allowing you to sell the upgrade, causing you to recieve additional tablets.