Item description:

Load the first one. i think its 17th july. open your inventory and the shield weaver outfit treasure box.
You should get:
Got the Shield-Weaver Outfit

then load the second save slot. this is the last corrupted zone. i think its the hardest one. sorry for that.
but with the shield weaver outfit its pretty easy.
after completing the zone you should get:
All Corrupted Zones Cleared
All Transport Machines Killed