[mrzepecki]

I have:
Router ModelBuffalo WZR-HP-AG300H
Firmware VersionDD-WRT v24-sp2 (06/23/14) std - build 24461
Kernel VersionLinux 3.10.44 #10975 Mon Jun 23 03:40:24 CEST 2014 mips

I'm trying to upgrade this router using WEB UI firmware upgrade option but router always says that upgrade was successful and after restart an old software is being loaded.

I was trying many different files from Buffalo site and from DDWRT but the effect is always the same. How can I upgrade this router?

[egc]

Unfortunately you are posting in the wrong forum

The General Questions forum is not for asking router specific questions, see the second announcement in that forum: STOP!-READ FIRST: This area is NOT for router help! READ!

See the forum guidelines with helpful pointers about how to research your router, where and what firmware to download, where and how to post and many other helpful tips:
https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=324087

No problem as I will transfer this post to the appropriate forum.

[bushant]

Have you tried a non chromium based browser such as
Pale Moon, Waterfox (3rd Gen 78 or Classic 56), Firefox ESR 78 Portable or Firefox ESR Legacy?

Command line upgrade always works for my WZR-HP-AG300H.
https://wiki.dd-wrt.com/wiki/index.php/Installation#Method_3:_Flashing_with_Command_Line

If you are still on Buffalo branded version of DD-WRT you will need to use the buffalo_to_dd-wrt file.

[the-joker]

Make sure you use the correct file for upgrading via webif e.g. wzr-hp-ag300h-dd-wrt-webupgrade-MULTI.bin

Also, you are using a really old unsupported firmware build 24461 which you need to do nvram reset and reconfigure manually.

Your builds are here https://ftp.dd-wrt.com/dd-wrtv2/downloads/betas/2021/12-16-2021-r47853/buffalo_wzr-hp-ag300h/

Your best bet is