Apache SSL error: Private key not found
WARNING: Do not ever post your private key on internet. Do not even copy it to another computer, workstation etc. It must be kept as private as possible.
SSLCertificateKeyFile requires a Private Key. This key is usually generated before CSR or at the same time. Search for a file that starts with a line containing: BEGIN PRIVATE KEY
CSR (certificate signing request) is required only when you ask to sign the certificate. After that you can discard it.
If you lost the Private Key you will need to generate a new Private Key, then generate a new CSR and ask the CA (certificate authority) to sign the CSR again.