TVHeadEnd rejecting login

[livetv]

Just installed the lastest XBian with Kodi 16.1 on a Raspberry Pi Model B+. Logged in and installed tvheadend with apt-get install xbian-package-tvheadend, rebooted and then attempted to access http://<IP address here>:9981. Web page appears and prompt for tvheadend login pops up. Copy and paste details from .hts/tvheadend/accesscontrol/1, but get "Login Rejected, try again?"

Is this a known issue with a fix? Or was the install procedure wrong? Or something else?

Any constructive assistance or questions welcome. Hoping to get OTA TV soon.