I received a laptop for repairs, among other programs I installed Malwarebytes. Windows Defender real-time protection crashed, it was not possible to start it, if I slid the bar to on it automatically went back to off. At this moment I didn't put the blame on Malwarebytes, I did a repair install with a Windows iso-file. This didn't fix the issue, I did some additional cleaning, used the Malwarebytes support tool to clean, Norton removal tool, also got help from the Bleepingcomputer forum with fixes. I'm not 100% what did it but Defender started working again.
Great, what a relief. I went ahead and installed Malwarebytes free version because it's a great program to have. The 14 day premium trial activated and Malwarebytes took over Defender, because it's now also an antivirus. I'm not interested in premium so I deactivated the trial and Malwarebytes seemingly removed itself from the Windows security center. The problem now is identical, it's not possible to activated Windows Defender real-time protection. I've done all the steps I did before but nothing works. There clearly are some problems with Malwarebytes, I'm very disappointed because I've been so happy with the program in the past.