Have you got the ‘Your Premium trial expired‘ message box on your computer that looks like this?
This is most likely because your Malwarebytes Anti-Malware software was updated recently which gave you a 14 day trial that has expired.
If you want to revert back to the free version, select ‘Stay downgraded–I don’t need Real-Time Protection‘ and click OK
Otherwise, if you would like to purchase the Premium package with live Ransomware protection, you can purchase it here.
If you already have a paid subscription and have got this message, I would advise to contact Malwarebytes Support.