Could not add new interface - Openvpn client

RouterOS General
1

I can’t understand, after setting my windows openvpn server, I successfully imported ca.crt and client.crt via ftp to my cpe,
when I try to add new interface I get this error:
Could not add new interface - No certificate found (6)

where do I go wrong?

2

You have to have a running certificate installed before you can create it. Check out the “Import Certificates” section of this wiki page on how to do it.
http://wiki.mikrotik.com/wiki/Manual:Create_Certificates

Here is another good wiki page on it:
http://wiki.mikrotik.com/wiki/OpenVPN_Configuration_Step_by_Step