I have collected all 10 postcards, but I can't put the 10th postcard into the mailbox. I triple-checked every location using a guide and the postcards are gone. The only place I am unable to check again is the postcard you get after activating the blue trinity mark in the first district. I highly doubt that I didn't open the chest there, but if I didn't open it for whatever reason, am I screwed? Is there any way to fix this? RobotRebel - 2 months ago
I managed to get an angle on the balcony and saw no chest. I checked all other locations again and still there are no new postcards RobotRebel - 2 months ago
If there isn't a chest there, perhaps you didn't open it, or reloaded a save file to before you opened it? IIRC, all chests stay there, either open or closed, but never disappear, so it not being there whatsoever makes me think that you didn't get that one. Eevee-Trainer - 2 months ago
You can reach the balcony using glide later in the game. Though this only helps if that is the one you are missing. ManyHours - 1 month ago
This question was asked more than 60 days ago with no accepted answer.