If you have for example RapidSSL SSL certificate with intermediate CA, you need to combined private key, SSL certificate and intermediate CA into PKCS12 file.

There should be hint ( message popup ) if you import certificate with chain, that you need more steps ( Import, Activate, Restart , Update Certificate Chain, Restart ). There is KB article for it, but this is not uncommon situation.

by: David K. | over a year ago | Administration