When installing a Windows application, the following message appears saying that custom functions can not be used because of a certificate.
User-defined functions can not be used in this application because the certificate that signed the deployment manifest for the add-in or its location is untrusted.
Contact the administrator for further assistance
Error message during installation
Where is the certificate?
For Windows projects (WPF, Addin, Winforms, VSTO Addin, COM) you will find the certificate under Project-> Properties-> Signing.
The solution is pretty simple. You do not really have to add a confidential certificate to the project.
Simply turn off the Signing-> Sign the ClickOnce manifest option-> OFF
Solution 2: Certificate via Windows Store
You can create a certificate through the Windows Store if you have a Microsoft Developer account on Windows Store.
Properties and settings of the created certificate via Store
For distribution purposes, you can then export the certificate.
Copy to file->
Certificate Export: DER-encoded-binary x.509 or base-64 encoded