"Retired Person"

Someone appears to have misunderstood exactly what this means. Setting a person to "Retired Person" strips out all data about that person apart from a name and an ID. They are in the game by name, nothing more. Setting Michael Carrick and Per Mertesacker to this does not make them staff members, it gets rid of all of their data which is why they don't appear in-game in their correct roles.

This person type should only be set on people who have retired from football completely and have no active participation in football anyway. You should be using the person type "Non-Player" for players who retire and go into coaching/management.

thats nor easy to do automatically

players have to be changed to staff

PA/CA has to be added
Attributes must be set, etc

there are lots of failed changes in the DB here due to this issue

it happens when a player leaves a club and on an earlier draft of the update to the file he is set as retired(wrongly IMO and thus taking him out of the game)
later on that ex player takes a non playing job and the DB is updated again but these changes fail due to the retired issue

once again IMO when this happens just change him to a non player its simple and easy to do that way he is still in the DB and can be edited later to take up his new job etc etc

for those who are not aware its not the end of the World... you can get the retired person back via the changes tab under his details select the retired one and remove follow the prompts save and reload DB you may on some occasions have to do this twice due to a slight bug with the editor(remember to back the file up first)

it can be time consuming if you have to do loads but you can get the person back in game and his failed changes will now work correctly, in the last file there are 27 so not too bad the likes of Mertesacker/Carrick who should definitely be in the DB as they have very high profile positions in the game now

There is another workaround if you are in a save-

using the SI IGE you can edit a person in the DB say a regen to be the retired ex player hope this helps but as MG @metal_guitarist says in the OP the retired option is not being used correctly which is a shame as the huge work done here creating the file is fantastic and much appreciated but this needs addressing

I've just edited the file myself as outlined in my earlier post

But you can only do this with the ingame editor surely?

I outlined what to do with both pre game and IGE above
Will be time consuming if you want to bring every retired ex player back. Ones with failed changes not too bad