Malwarebytes Premium will usually update itself without any issues but if you find you do have a problem, usually after an update, our best recommendation is to uninstall and then reinstall the program.
Don’t worry if you can’t find your license key since the program will remember it when you reinstall.
You can uninstall the program from Add Remove Programs or just type Malwarebytes from Search in Windows 8 or after clicking the Windows Orb in Windows 7.
You’ll probably be prompted to reboot the system. After the reboot visit http://www.ninite.com/malwarebytes to reinstall the software and everything will be working as it should: