You may get an error as Invalid License in cases where one product key is activated or used on more than one system at a time In order to resolve the issue, need to cross in your network or premises as one product key is activated in one system only If one product key is activated in two systems, then uninstall it and use it on only one system at a time If issue persists then you may also contact their technical support team from https://www.quickheal.co.in/support.