I would never do a clean install to get Malwarebytes or any other software working, or for any other reason. In order to see if there were any issues caused by upgrading from v2 rather than doing a fresh install of Malwarebytes, I uninstalled it and removed any remaining traces with Comodo Programs Manager. I then ran the Malwarebytes Anti-Mwlare Cleanup Utility to remove any traces of MBAM v2. I reinstalled v3 again (and my license information had been retained), and started running a Threat Scan. I didn't take long for me to stop the scan, as just as last time I ran it, CPU use is ridiculously high, exceeding 90% at times. That's reason enough for me to give it a miss until a stable version is released, and I'm uninstalling it now.