There is an issue with Malwarebytes disabling Windows Defender in the Windows 10 Creators Update.

We are working on a solution, but it will take a little time to implement/test/etc. The current workaround is to go to Malwarebytes -> Settings -> Application and set Malwarebytes to never register with Windows Action Center.
For more information, please visit:
https://forums.malwarebytes.com/topi...eators-update/