pop up message Critical Error, your start menu isn't working

[Burrow1]

I just purchased my laptop 8 days ago. I did not have any problems with it until 2 days ago.  I opened my laptop, and enter my PIN. My home screen appears like normal. when I click on the start up menu (little blue square on the bottom left of the screen) I get a popup message :Critical Error Your start menu isn't working. We'll try to fix it the next time you sing in. Sign out." I sign out and wait a few seconds before signing in again and nothing changes. I can get into my apps etc just not anything from the start up menu button 

[banhien]

@Burrow1 

When you right click it, can you see a Menu ? You can select options on the list

Regards.