Question: I publish my exe and activate auto updates.

But when I compile the exe, there is an error:

> 
> Severity Code Description Project File Line Suppression State Error An
>  error occurred while signing: Failed to sign
>  bin\Debug\app.publish\myapp.exe. SignTool Error: Invalid option: /fd
> 
> 
> 

So I couldn't publish.

When I try to uncheck "Sign the ClickOnce manifest" the error is gone
but I couldn't install the package because Windows doesn't allow and the Windows Defender SmartScreen blocks my app because there's no certificate.

I have to add a certificate from "Sign the ClickOnce manifest" but now it gives the "SignTool Error: Invalid option: /fd" error.

How can I solve this problem?

Answer: 
I had to change the Signature Algorithm to sha1RSA from sha256RSA
Go to the myapp.csproj file, which is the project file, and search for 'SignManifests' PropertyGroup, change the value to false, and the error disappears. This worked for me.