In your post you mentioned "currentlPlayingTitleYear" I thought it was a typo in the post, but sure enough when I changed it to "currentlyPlayingTitleYear" Indigo complained.
That would be a good, old-fashioned typo :-/
Looks like Indigo doesn't like the large thumbnails that get downloaded when I add them to a control page. Any way to work around this? I'm seeing:
You should be okay with most of the Thumbnail art, but some of the actual large-scale art is pretty high resolution and I suspect that is what you are running into; if I am not mistaken Indigo limits those refreshing image sizes because it could kill reflector bandwidth (not to mention your device's data) if it were refreshing too often.
I happen to run into that the other day as well while playing around with some control pages; I want to see if Python has a method to allow me to resize an image and that should solve your issue as the permanent fix. In the meantime, you could possibly use AppleScript to resize it (download full size and then use AppleScript to resize/save it to a new image, which is the one put on the control page). That is a clunky work-around but hopefully you wouldn't have to do it for long if you don't feel like waiting for the better fix.
Adam