Hi.
Feels like this is more a server side issue.
When the server is under heavy load, for example, when there are 13k players online, this issue happens.
When the server is below around 9k players, I've never had this issue, and have been testing this for some time.
This kind of action should not even be handled server side, but for some reason something in this change goes through server, which is then probably low priority due to the network priority system nostalrius is behind.
It doesn't matter if the folder is read only or not.
Always had this issue when the server is under heavy load, but never when there's less players online.
That's my wild guess at least.
-Kayako