Well you get the idea, here it shows that cron plugin wasn't loaded, let's proceed :)

There's an unsatisfied dependency on plugin Tasks. Please see nearby if Tasks plugin has any load problems.

I highly recommend to simply run checkinstall utility install of "make install" which will create and install a package from your custom sources which would be both easy to remove/upgrade and would satisfy ajenti-v-nginx requirement.

I'm seriously afraid that Ajenti won't be useful to people who don't know what Apache is but nevertheless try to configure it.

Please try downgrading python-gevent-websocket. 

Please upload output of apt-show-versions somewhere, it's likely incompatible versions of python-gevent-websocket and python-gevent-socketio

If you had OS sync, you could just use passwd to change password of respective user. Another (insecure) option is to disable auth temporarily.

It might not work if a) you didn't restart Ajenti b) you have password sync (OS/LDAP/AD) enabled