Ilum Exploration

 Just to elaborate on the the statement made earlier. I got my last 20% in the under water cave as well. There are three exits out of the water. When you first jump down into the water head left and into that cave and climb up out of the water, there is an echo. 

Exactly same problem on Ilum, two secret, both find. But when I get back to game, only one is found. But if I walk to the areas with secret, there is no way to pick it up again.

There is a roundish shape room in the crystal caves with a save point and a hole in the middle, drop down that hole and there's a ledge at the bottom you can stand on

This worked for me thank you

Thanks found it!

Perfect Thank you

Actually, there's an easier and more fun way to get there - go into the first chamber where there's a Security droid, some storm troopers, and a single probe droid, and use your lightsaber to break through the icicles in that room, and you'll wall run into a secret cave, then find a big ice slide, which will take you down to the force essence down there. Then just climb up the hole.