Also know as Multilaser RE039, this is a rebranded TP-Link TL-WR741ND v1 from Multilaser (brazilian vendor), and will only accept firmwares with Multilaser vendor ID bytes (in the file header).
Other compatible firmwares(TP-Link, OpenWRT, Gargoyle, DD-WRT) use different vendor IDs, or does not come with those bytes (which are needed for switching the stock firmware, otherwise you will get TP-Link error 18005).
Steps:
For the next firmware updates, you don't need to change vendor ID bytes again.
Everything can now be done like it was an original TL-WR741ND v1
* This can be applied to many other rebranded routers using the same hardware.
How to change vendor ID bytes:
(2) is router model
(3) is vendor ID
All the internal images are the same as RNX-N150RT and TL-WR741ND v1/v2