sounds like the classic bug of the recovery console of many D-Link devices, which results in Linux clients + any browser to stall.
Did you try Windows + good old Internet Explorer already? (A VM might do aswell. one of Chrome, Firefox on Windows did work as well)
D-LINK recovery mode (DIR-882 DIR-878 DIR-867) - #8 by Pico (there were some other better threads in the forum discussing the issue)