For Apache error message is:
[Tue Jan 23 12:51:37 2017] [error] Unable to configure RSA server private key
[Tue Jan 23 12:51:37 2017] [error] SSL Library Error: 185073780 error:0B080074:
x509 certificate routines:X509_check_private_key:key values mismatch
You need to make sure you supply all intermediate certificates. You can also combine them in a .pem file like this:
your private key
your certificate
(intermediate) CA certificate lowest in the hierarchy
other CA certificates higher in the hierarchy...
(intermediate) CA certificate highest in the hierarchy
Make sure there are no extra lines and carriage returns.
