so far, there have been only two causes for this kind of error - either a damaged file, or a background program blocking access.
In the case of a damaged file, you need to reinstall MV - but that is the unlikely cause.
Most cases, the cause was one of your background program blocking MV - anti-virus, anti-malware, parental protection programs, local access control programs and so on can stop any program from responsing, and because MV uses web technology on local files (neccessary for being able to deploy to different devices), this has sometimes confused the antivirus programs into believing MV would be an online virus trying to infect local files.
Please search all your background programs (and especially their log files) until you find the one that is causing this, and then whitelist MV there.