DO12 - Can't connect to FTP (SFTP)

I'm trying to connect to SFTP using DOpus 12 Beta (12.0.8 x64) but I am getting this error: "an error has occured. Unexpected ftp error".

I'm using a private key (.ppk format) and specified a username.

Here is the last lines of the ftp log:

Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Reading private key file "C:\Users\Nicolas\Documents\keys\admin.ppk"
Offered public key
Offer of public key accepted
Connection closed

I don't see any problem here.

Note that I can connect just find to the same sftp with putty for example.

I meant I have no problems with Filezilla (sftp mode).

Note that Filezilla asks me for a password, DOpus doesn't.

Is Filezilla configured in the same way? Is it using the ppk in particular?

(Please also link your account.)

Yes, Filezilla is configured the same way and uses the same ppk.

Thanks for the report, it's because your certificate has a password which Opus doesn't currently support. We'll add this in the next beta.

I can confirm this is fixed in latest beta.