Originally Posted by snowfly
I have spoken with Trustico support, and they have said the reason for the error is:
"You have lost the matching private key, that was created when you generated the CSR"
The SSL CSR was created via ISPConfig, so where is the original matching private key?
The ssl key is in the ssl directory of the website. It does not get chnaged when you upload the cert, so you did not lost the key as the trustico support guessed. I explained you above the possible reasons for the error message, either the trustico ssl cert is not based on the csr generated by ispconfig or you accidently generated a new csr and key instaed of saving it.