Ever since I upgraded from Malwarebytes Anti-Malware (version 2.something) to Malwarebytes 3, I've had issues with video rendering using madVR. Every couple minutes, the video freezes for two or three seconds and all frames are dropped. This occurs no matter the file size of the video being played nor the settings used within madVR. This is not a problem of inadequate GPU performance, since render times remain <10ms (anything below 41.7ms would not cause frame loss in a 24fps video anyway).
To clarify, madVR is a separately installed renderer that's used within a media player (in my case, MPC-HC) to render video after doing some processing to the contents of the video (e.g. scaling algorithms to enhance picture quality of upscaled content). It's not a separately running process.
I know that the culprit is Malwarebytes, specifically the Ransomware Protection component of the Premium version's real-time protection layers. I know this because when Ransomware Protection is the only thing enabled, the frame loss problem always happens (every couple minutes or so). When Ransomware Protection is the only thing disabled, the problem never happens. I can reproduce it with 100% reliability every time with no exceptions, over and over again. As further confirmation, the problem never occurs in the media player if I use a different renderer than madVR, nor does the problem occur if I use a different media player.
One more thing: adding the media player process to Malwarebyte's process exclusion does not resolve the issue.