in my Flas CC not the option I appears in pictures: Export all bitmaps as Sprite sheets, this happens to someone else?? Help!
Export as spritesheet in publishing settings is a feature of HTML5 Canvas documents, and only recently was added. If you're using an AS3 FLA, you won't get the option. If you didn't update Flash Pro recently, it will be missing from HTML5 Canvas FLAs too.
I am having a similar problem. Having converted my game from AS3 to an HTML5 Canvas Document all existing Movieclips were included in the Spritesheet when first published. So far so good. Then added a new asset to the project but on publishing this is not in the Sprite Sheet and not included in the auto generated .js file. How can I update the project to include old and new assets in the same files?