Hovering over the like or fav button is an intentional "Freeze Challenge." Nothing bad will happen to your computer or your Scratch account; the tab will simply freeze. To get back to the project, just close and reopen the tab to fix it. Only the tab is frozen, not your computer!
⚠️ THE LIKING CHALLENGE: Hovering over the Like button is a deliberate "tab-freezer" prank! How to get back when it freezes: Don't worry, your computer is fine! Just close the tab (Ctrl+W). Re-open the project and continue having fun on scratch.