Just FYI, D-Link has this in review and is aware of the Year bug for this specific Rev. Looking into other problems as well. One possible issue is that this specific Rev was sold 5 years ago and has since not been sold and newer Rev's have already come to market. Not sure if and when this might be fixed for this Rev or any older Revs of the 615 series. I recommend that if users are critically effected by this, to phone contact D-Link support and inform them of this issue with your router and see if there is any information on a fix.
If users need a faster solution, I recommend a newer DIR 6 series router to get into. DIR-626L, 636L, 645, 657 or 655 are all good routers and are not effected by the Year bug.
Please be patient.