CAD, the second link has no bearing on the question, and I don't think a new user can be expected to understand why the first might.
Alfa60, it sounds like the problem occurs when it "asks to select the movie on a big list of similar names." The plugin has run a search at one of the source sites, and is asking you which movie to select from the search results. The dialog includes check boxes for selecting multiple items. The only purpose for this to run a search for something like "Lord of the Rings," and then select all three. The result will be to add and download information for three movies in the series all at once.
Most of the time, however, you'll only be interested in properly identifying the one movie you're trying to add. The fastest way to do that is to double-click on it in the list. If you're not sure which is the right one, select the most likely one and click the link at the bottom to open that page in your browser. If that's hopeless (and occasionally it is), do your own search at the source. When you find the correct movie, cut & paste it's URL into the URL field of the record and run the import again. When it has the URL it doesn't need to do a search, and will download the information directly.