Can't build an app for distribution after joining existing enterprise developer program

Question

I joined an existing enterprise developer program. I was able to run the app in developer mode, but had issues with building and archiving. The certificate

Answer 1

The certificate is only half the necessary parts. You also need the key for the certificate.

Open Keychain Access on your Mac and select the Certificates filter on the left. When you select the certificate for your Enterprise Distribution, make sure you there is a green check mark in the top section next to a message that says "This certificate is valid" (bubble 4 in picture below).

Also, and this is likely your problem, you need to make sure there is a triangle next to the certificate that allows you to expand it (See bubble 3 in picture below). Without that, you have no way to code sign using the distribution certificate. You will need to get the private key from the person who created the certificate, or get the key off of the machine that was used to generate the certificate signing request file (CSR) used to generate the cert.