The most recent patch for Dragon Age: Inquisition did not address the problem many players are having with mosaic collectibles. Namely, the collectibles do not all exist in the game. In The Hinterlands there should be 12 pieces, but there are only 11, with one being inaccessible (outside of bounds). Thus, players may not want to try to complete this quest until there has been a patch.
This is not the only fetch quest that is broken; Solas’ quest remains impossible to complete for anyone because the War Table mission that continues it is not accessible. Further, many players have found themselves short by five or six shard pieces even after collecting every single one they could find.