Hover over each fragment, as long as the quest is done and you've gotten the aspect purchase etc done - one fragment, even though it might look greyed out, should be available. The rest will display one of 2 error messages, either mentioning worlds first or needing to buy aspects/fragment used during the campaign. If you're certain none of them can be bought, grab a clip showing your quests, the fragment purchase screen at the pond (hover over each of them), and the aspect purchasing screen then link to it here.