I wanted to add some clarification as well. when I log in to the console on Amazon Web Services, I use my ppk file for authentication, which is what I think is causing the issue as I can't use that for the web admin. The passwd command results in this:
login as: openvpn
Authenticating with public key "imported-openssh-key"
Welcome to OpenVPN Access Server Appliance 2.0.5
openvpn@openvpnas2:~$ passwd openvpn
Changing password for openvpn.
(current) UNIX password:
passwd: Authentication token manipulation error
passwd: password unchanged
openvpn@openvpnas2:~$
Note the (current) - I am not able to change without it. I've looked at some of the information about pam, but I figure that part of this is related to the administration database. The AMI I used was ami-cfa5afa6.
I've also tried using the openvpnas password but it does not work. Looking back I did not use the User Parameters section to supply anything, so I am curious if I should just rebuild and redeploy?