While I don't pay the mod much lately due to other commitments, I would still do a quick login every now and then to check up and update the client.
However, after the release of D2:R, I was worried the source game got assimilated (which will cause a lot of issues) like WC 3 so I booted up the game again just to check.
After updating and pressing play, the launcher opened up as per usual but there is no game client. I pressed a second time and it said that there is already an instance running.
I checked all the settings and there isn't any problem.