mIRC uses the SSL_CTX_use_certificate_chain_file() OpenSSL function to load the certificate chain file. The function lists the following as reasons why it might report an error:
The certificate file does not exist or you do not have permission to read that file.
The certificate file that contains the certificate chain is not in PEM format.
If you loaded a private key file before issuing this function, the private key in that file does not match the corresponding public key in the certificate.
If the files are working for everyone apart from one particular person, it may be that there is something with that person's mIRC and/or Windows configuration that is causing the issue.
The
SSL page on the mIRC website includes two versions of OpenSSL. If you delete all of the OpenSSL files from the Windows and mIRC folder and re-install them from the SSL page into the Windows folder, does one of those versions help resolve the issue?
