Languages X-Ray supports: Català, Dansk, Deutsch, English, Español, Français, Italiano, Lietuvių, Nederlands, Norsk bokmål, Polski, Português, Română, Ελληνικά, Македонски, Русский, 中文, 日本語.
If you've installed 64-bit calibre, you should install 64-bit Python. If you have 32-bit calibre then download 32-bit Python. Select "Install Now".
Enable "search people" option for nonfiction books and novels that have character pages on Wikipedia to add people descriptions in X-Ray.
This plugin requires access to https://files.pythonhosted.org (download dependencies) and https://raw.githubusercontent.com (download NLTK and spaCy model) at first run, and https://wikipedia.org every time if X-Ray is enabled. These domains might be blocked in some countries.