I have Intel NUC with Ubuntu 14.04.1 LTS, 3.13.0-40-generic x86_64 and Plex server 0.9.11.1.678 and PHT running on the same system.
I have just upgraded to the newest PHT build 1.3.1 and ran into issues with authentication. I tried both PIN at plex.tv/pin and user id and password, but was unable to sign in. I had to downgrade (restore from a backup) the previous version of PHT 1.2.3.dev-git, which works fine. I have attached the log files in both cases. The only not standard thing in my setup is that I have kept curl at version 7.34 to avoid issues with some channels. I don't think it is related, but mention it just in case. For more details you can see my post here:
It seems like many people are having this issue with PHT 1.3.1, so lets hope this will be fixed quickly.
This post in the other thread was very helpful. Thanks.
For those that have updated, navigate to /var/cache/apt/archives. Find the last version of plexhometheater which will likely be 1.3.0 and install it with sudo dpkg -i. To prevent it from being upgraded with the broken package use: