Hello! I had the same problem, but with an V7 version. I had to update first a middle firmware (TL-R480T+_V7_tmp) and after that the update worked. Look for such a firmware update and load it first....

Model : Hardware Version : Not Clear Firmware Version : ISP : Hello admins! I recently opened my account and just sent a question concerning TP-Link TL-R480T+ and a TP-Link TL-MR3420. I have been...

Model : Hardware Version : Not Clear Firmware Version : ISP : Hello! I have a broadband router TP-Link TL-R480T+ and a TL-MR3420 (V 2.4) with 3G dongle and would like to combine the two, i.e. using...