trakt.tv | A Trakt.tv API wrapper for Node.js | REST library

I am trying to do a simple windows app for picking a random movie from my trakt.tv watchlist, I used tkinter for a basic gui, then use random funciton to choice a movie from a txt file, then with trakt library fucntion I get my watch list from trakt and record it as a txt for random choice, define a function to one of my button to pick a random movie from there and show it in text box. It's working in that way but now I want to add overview, rating, year information related to the random movie, it is working good for just "some titles" but some movies get following error message; "trakt.errors.NotFoundException: Not Found - method exists, but no record found"

I think some movie's names can't get direct result from trakt.tv, so what could be solution for that? For example; can I get trakt_id from a watchlist and use it for all other information and how? I check library files but it seems get the info directly user list website and I couldn't figure out how can I get any other information from there. Also how can I add a random fanart under the buttons related to movie which choiced by random?

Sorry my English and if I can't explain my questions well :)

My code is below;