socat[13362] E SSL_CTX_use_PrivateKey_file(): error:0906D06C:PEM routines:PEM_read_bio:no start line
So make sure your certificate files ( ca-cert.pem and server-cert.pem ) have
-----BEGIN CERTIFICATE-----
and
-----END CERTIFICATE-----
lines.
That your key file ( server-key.pem ) has the lines
-----BEGIN RSA PRIVATE KEY-----
and
-----END RSA PRIVATE KEY-----
If you copied their contents on Windows system, then you need to verify that they didn't get a carriage return on the end of any line in the files.
Hope this helps.
Cheers,
Aaron