Unable to verify the launcher

[merex]

If the problem still foes on, might as well deactivate your Antivirus and Firewall, they seem to prevent suspicious app  to be launched. They see the KillerSource app as a suspicious app because it has been downloaded to an unknown source. so try to deactivate them or put the KillerSource app as an exemption, so that they won't block its launch. Hope this help, Arigatou!