FYI, I had a "nice" conversation in the Malwarebytes Forums:
https://forums.malwarebytes.com/topic/309490-have-you-all-stopped-making-updates/
Unfortunately, there won't be any further definition updates for Malwarebytes' Anti-Malware Pro 1.75.0.1300. They have deliberately stopped rolling out current definition updates for this version. After the end of support for Avast Free Antivirus 2015, Malwarebytes Anti-Malware 2.2.1.1043 and now Malwarebytes' Anti-Malware Pro 1.75.0.1300, the air is getting very, very thin for anyone who wants to run an antimalware programme with real-time protection on a machine with an SSE only CPU that is still receiving current definition updates. All in all, bad news!