When talking/trading with Kortan in the Ardougne General Store, he cannot be traded with through either option (Trade/Talk-to dialogue). I found this bug probably about a week ago? Just haven't had the time really to do anything about it. Thanks for looking at my post. My IGN: Chrisc70

I overheard the developers speaking upon this issue earlier yesterday.
This bug has also been previously logged into the bug database by another developer.
This will be fixed in an update soon to come!

Thanks for reporting this bug Chris! - Seth

Reference: blitz/shops#7