Seeing as Apple are in no rush to help me fix this issue, I am going to have to create a new Apple ID, pay the $100 to create a new apple developer account, and sign my apps with this new apple ID/dev account. My question is what could potentially go wrong with creating a new apple ID, then signing out of my apple ID on my mac, then signing in with the new ID? How does this impacts certs etc? Is it better to factory reset my mac then sign into it with my new apple ID?

Thanks eskimo, I've emailed support and requested that they revoke one of my developer ID certs, or increase my limit above 5.

I solved this issue, well, it turns out there was no issue. I successfully signed and released an app even though the certificate I used to sign it was 'untrusted' and had no root certificate. Neither of these issues prevented the certificate from working as it should.

I've checked each certificate and they all have trust settings as “Use System Defaults” for “When using this certificate” and “no value specified” for the other pop-ups. Evaluation (generic) of my Apple Development Certificate (not expired) returns Evaluation Status: No Root Certificate Found Certificate Status: Good Evaluation (generic) of my Apple Worldwide Developer Relations Certification Authority (not expired) returns Evaluation Status: No Root Certificate Found Certificate Status: Good

To clarify, none of the certs had custom trust settings, I fixed the issue by deleting all the apple-related certs and re-downloading them.

Thanks Quinn, This advice prompted me to reinstall my certs and the issue has been fixed. However, my Apple Development Cert now has the green tick and "Certificate is Valid" - but when I evaluate it (generic) Certificate Status reports "Good", but Evaluation Status reports "No root certificate found". I am trying to notarise an app with this cert and I am getting the error "The binary is not signed with a valid Developer ID certificate." Even though: security find-identity -v -p codesigning returns a valid identity, and I'm guessing the notarise error is due to the missing root cert.