[bsoriano]

@jurialmunkey, thank you! I had not thought of the plugin path for cast. If I do that, then the visibility condition would be just numitems > 0 or isupdating, correct?

Yes, that's correct. Plus the condition that you use to hide this list if local cast is available -- I'm assuming you only show this online cast list if cast isn't available locally in id="50".
 

EDIT: @jurialmunkey , using the cast plugin path works well, but it seems the plugin does not fill listitem.label2 for the character/role.  What is the property where the plugin stores the character/role for the cast?

ListItem.Property(character) - The name of the character that the cast member plays.
ListItem.Property(job) - The job that the crew member does (e.g. Director, Executive Producer, Screenplay Writer, Sound Editor etc.)
ListItem.Property(department) - The department that the crew member is from (e.g. Directing, Writing, Production, Crew, Art, Sound etc.)

Character is only relevant to cast lists. Job and Department are only relevant to crew lists.

There is also a catch-all property ListItem.Property(role) which will show character for cast members and job for crew members. 

@jurialmunkey , thanks once more! I am only showing the online cast when tmdb_id is not empty, and I am showing the local cast when tmdb_id is empty.  I guess this is not ideal, since if the item is cached, container 50 will be filled.  I suppose I should only show the online cast if container 50 has 0 items?

Regards,

Bart