I think I figured out a solution. I installed 64 bit java manually after running into some unrelated errors. After the installation, TVDB has been able to retrieve multiple seasons of episodes without a hitch.

Thanks for the responses guys. That makes some sense about the 403 error as I commonly use a VPN, however even my own vanilla IP address doesn't receive results (maybe TVDB doesn't like me :cry: ).

Just a data point, but I was able to retrieve episodes multiple times going through the different ...

I am probably doing something incredibly dumb but I can't seem to figure it out. I can retrieve episodes when using AniDB, TheMovieDB, and TVMaze but not when using TheTVDB.

Here's a screenshot of an example of the issue.

http://i.imgur.com/bfOuanE.png

Here is my system info

C:\>filebot ...