Maintenance for the week of August 3:
• PC/Mac: No maintenance – August 3
• ESO Store and Account System for maintenance – August 4, 5:00AM EDT (9:00 UTC) - 4:00PM EDT (20:00 UTC)
Figured it out, use the grappler to go back to the first one. Move it to another plate on the same level then drop down to the were you moved the second block. Now, the door should be open. Move the second block inside and the final door should be open.