This error occurs because the PVK file does not start with the bytes
B0 B5 F1 1E
which is the magic number of (at least some) PVK files.
I tried generating a private key with CuteFTP and it did not generate a PVK file. Instead it generated a KEY file. Did you convert this file to a PVK file somehow or did you get CuteFTP to generate the PVK file itself?
As an alternative you might like to try using OpenSSL to generate a key/certificate pair in the PEM format. You can then convert the key file to a PVK file using
this utility. You can find a Windows version of OpenSSL
here and details instructions on creating keys with OpenSSL
here. In short you generate the key with the command:
openssl genrsa -des3 -out privkey.pem 2048
and the certificate with the command:
openssl req -new -x509 -key privkey.pem -out cacert.pem -days 1095
- Hans (EDT Support)