Clickonce App Doesn't start with Windows 1803
Yes, frustratingly I also experienced this today. Presumably a security update that they'll release another patch for given this is quite a pain for developers and users of small business apps.
Rather than disable Defender or SmartScreen I chose to add my deployment website to the Trusted Sites in Internet Explorer and that then re-instated the warning dialog and my app updated and ran as before.
Really annoying given the nature of the issue and how long it took to figure out, but at the same time I had to use IE today, which is a rare event nowadays.
