Same here, on an HP laptop running Windows 10. What finally worked was downloading and using the cleaner/reinstall tool from a slightly older thread here: (Look for reply by Porthos.) Note 1) This tool creates two text files on the Desktop: an activity log (for you to attach to a plea for further assistance, if you need it) and your license key. (I had already copied all my subscription/license info from my Account settings ahead of time, just in case.) 2) One complaint about this tool is that you're not given the option to reinstall the latest version. I DID get this option, but the pop-up boxes asking you questions about this or that, including rebooting and reinstalling, are very small and so possibly easy to miss. (?) 3) After it's all over, Malwarebytes will still show that it's unhappy (red bang over the M icon in the Systray), but that's only because it wants you to run a scan. All is now well for me, including after multiple reboots and one cold boot. 4) Separate but maybe not unrelated: last weekend this laptop was behaving VERY badly, and the culprit turned out to be MB using an insane amount of RAM: 3+GB. I did an "End Task" from Task Manager and rebooted, and that took care of it -- but just FYI.