This can be caused by the 'RTProtectionDaemon' process being disabled and not actively persistent in memory, not present in the install, was corrupted, third-party program conflict, etc. It's possible that the problem is caused by another component of the Malwarebytes program. I can mimic this exact problem whenever disabling the load and persistence of 'RTProtectionDaemon' process by 'launchd'. I don't like the developer's choice to make the Malwarebytes GUI dependent upon 'RTProtectionDaemon' process being active since it's primary function is Real-Time Protection, which is a service component of the Trial and Premium subscription models. You could attempt the following commands in terminal to determine if this resolves the issue.