NSInternalInconsistency Exception - findPlaylistByID is Invalid - What does that mean?

I am catching an error in XCode 4 without making any changes.  A screen shot of the error is attached and here is the code that I am suspecting is causing the issue.  Please help me out if you can, I am not sure why I am getting this error:  

e- (void)fetchVideoInfoForPlaylist:(id)aDict {
BrightcoveDemoAppDelegate *delegate = (BrightcoveDemoAppDelegate *)[[UIApplication sharedApplication] delegate];
BCMediaAPI *bc = delegate.bcServices;
PlaylistCacheObject *playlistCacheObj;
BCPlaylist *playlist = (BCPlaylist *)[aDict objectForKey:PLAYLIST_DICT_KEY];
UITableViewCell *cell = (UITableViewCell *)[aDict objectForKey:CELL_DICT_KEY];
NSNumber *key = [NSNumber numberWithLong:playlist.playlistId];

if ([playlistCache objectForKey:key]) {
    playlistCacheObj = [playlistCache objectForKey:key];
}
else {
    // request, stash in cache
    NSError *err;
    playlist = [bc findPlaylistById:playlist.playlistId videoFields:[NSArray arrayWithObjects:@"thumbnailURL",nil] playlistFields:[NSArray arrayWithObjects:@"videos", @"thumbnailURL",nil] customFields:nil error:&err];
    if (!playlist) {
        [[ErrorHandlerService sharedInstance] logMediaAPIError:err];
    } 
    else if (playlist.videos && [playlist.videos count] > 0) {
        [playlist.videos objectAtIndex:0];

        // fetch the thumbnai for the first video
        NSString *imageURL = [playlist thumbnailURL];
        UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]]]; 
        playlistCacheObj = [[[PlaylistCacheObject alloc] initWithData:playlist image:image] autorelease];
    [playlistCach开发者_如何学Ce setObject:playlistCacheObj forKey:key];  ;   }   

    }       

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The assertion is being thrown from BCPlaylistReadService, not PlaylistTableViewController. I suspect there's an NSAssert in there. I would guess from this that either playlist or playlist.playlistId is nil, but alternately playlist.playlistId might just be invalid as the assertion notes.