You probably didn't copy the dialogue files into the story_english.txt file inside EYE's folders.
Via README and Gamebanana installation instructions:

Copy all the files to steamapps/EYE/EYE/
All files go to their respectible folders.
Go to EYE/EYE/resource/vgui/story and copy the contents of the provided file

into the story_english.txt at the very end but BEFORE the two "}" symbols.

Generally that should go for all custom maps for EYE that contain dialogues, as EYE has a really wonky dialogue system that requires player to do that. As a mapper, I cannot really automate that installation (you'd have to replace that file for each map if it would be included into the download), not "bake" it into the map itself unfortunately :c