If you get an error message that you don't understand, Google it:
Error An error occurred while signing: Failed to sign bin\Debug\app.publish\UnFactor.exe. SignTool Error: No certificates were found that met all the given criteria. UnFactor - Google Search
It's very, very unusual for someone to be the first person to meet a particular problem, an din the case you are at least number 52,000 ...
Follow some of the links, read the explanations at the other end, and see what of them fits your situation.
We can't do that for you: we have no access to your code.