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Campos's avatar
Campos
Copper Contributor
Apr 24, 2026

Need help with ClickOnce deployment on .NET Framework 4.7.2 – "Unidentified program" warning

Hello,

I have a WinForms application built on .NET Framework 4.7.2 that I'm publishing using ClickOnce from Visual Studio Community 2022 (official Microsoft version).

Even after signing the application with a valid SHA256 V3 self-signed certificate, when I publish and try to install it via ClickOnce, I receive a warning saying the program is unidentified.

Additionally, when I try to install the application on a machine that has antivirus software, the antivirus flags the program precisely because of the missing/certificate validation issue.

How should I proceed? I'd like to know the correct way to publish with ClickOnce so that the application is fully recognized as valid by Windows, since I'm running into these antivirus validation problems.

Thanks in advance for any guidance!

.net
.NET Framework

1 Reply

  • Harold-Picado's avatar
    Harold-Picado
    Brass Contributor
    Jul 17, 2026

    Hi,

    The short answer is that Windows and antivirus software will never trust a self-signed certificate out of the box, no matter if it is SHA256 V3. To them, a self-signed cert is just you vouching for yourself, which is why SmartScreen and your AV are blocking it.

    If this is just for an internal lab or machines you control, you can bypass this for free. Export your .cer certificate from Visual Studio, copy it to the client machines, and install it into both Trusted Root Certification Authorities and Trusted Publishers (make sure to select Local Machine during install).

    If you are distributing this to the public, you have no choice but to buy a commercial Code Signing Certificate from a trusted authority.

    Also, make sure the "Publisher name" in your Visual Studio publish settings matches the name on your certificate exactly, otherwise ClickOnce will still throw the unidentified warning anyway