Something has changed between KeePass 2.17 and 2.18 that causes problems with using a password database on a remote host via a secure connection (IOProtocolExt). This (reportedly) works in 2.17+IOProtocolExt 1.5, but not in 2.18. The SCP programs supplied with IOProtocolExt can connect fine on their own, as can Putty, and this happens with or without a firewall on. When attempting to open a SCP or SFTP URL (scp://host:port/path/to/database.kdbx), KeePass always fails with the following message:
An exception occurred during a WebClient request.
Searching for host...
Connecting to host...
Using username "<username>"
Authenticating with pre-entered password.
Connection has been unexpectedly closed. Server sent command exit status 0.
Server logs show that the server thinks the password is incorrect (it isn't - the other programs use it just fine). Maybe a problem with sending the password to SCP? I've tested this on two computers (Windows Vista 64-bit and Windows 7 64-bit) and with two different servers (running different versions of SSH server). The .NET framework is the newest available in Windows Update (4.0.3, I think), if that matters.
Any ideas? Is anyone else seeing this?