I just noticed that, as I am studying a video using the video player VLC, that Hook was unable to recognize the application VLC. When I tried making a link to the running video, Hook asked, where is the application VLC located? So I went to the VLC app. But, VLC was faded out and could not be selected in a Hook menu.
I mention this in case it is of any use to Luc or to anyone. The situation was easily resolved as I made a Hook link to the file its self. Setting this file in a Hook menu launches the file which opens by default with VLC.
Perhaps I have not fully understood everything yet about using Hook but it would seem that Hook should have linked to an open video file. On the other hand, Hook cannot link to an open HoudahSpot file either (as the working file and not meaning a single item selected). Perhaps this is just my misunderstanding of how Hook operates but, as the VLC file could not be found by Hook, I felt it was worth mentioning.