Why Am I Seeing the "Incomplete certificate chain" Message?

This is maybe because:

• Certificates are installed in the wrong order.

  Sort the certificates with the root certificate at the end. For example, if you have three certificates, A, B, and C; and the root certificate, the order should be: certificate C - certificate B - certificate A - root certificate.

Alternatively, you can use an online certificate chain tool to fix the incomplete certificate chain.