The Secret of Tulak Hord- Unable to complete

If you are not in a phase but in the open world, it's possible that another player already clicked on the shards before you and you have to wait for the respawn. If the shards still do not glow after a few minutes, check if your planet has another instance open. To do this, open the world map and in the lower right corner, there may be a combobox where you can switch from "Korriban ( 1)" to "Korriban ( 2)". This fixes such a bug in most cases. If there is no second instance open (= the combobox is missing), wait for the maintenance tomorrow, then the servers are restarted and all objects are automatically respawned.

If you are in a phase (= inside a green door), you can try resetting the quest. To do this, you first have to walk out of the phase, then find your quest in the quest log and hit the Reset button. You'll have to redo it from the start but maybe the shards will work this time. Also, you can try resetting your personal phases - to do this, right-click on your portrait in the lower-left part of the screen and go to Phase -> Reset local story phases.

Let us know if these things didn't help you so we can investigate further.