Why is gmail not working in MacBook Pro, but working on mobile and Ipad?

I have 2 Gmail accounts. One is working fine. The other has stopped receiving messages on my Macbook Pro, but not on my Ipad or mobile phone? Any idea what is going on? Recently did a general software update, but it was fine after that for a day or so. And, my business partner who shares the same Gmail account is having the exact same issue. HELP!?