Hi, I just got a new Archer C5 AC1200.
Version 2.0 is supported: https://openwrt.org/toh/tp-link/archer-c5-c7-wdr7500
But I got version 2.1 (Model Archer C1200(EU) Ver: 2.1) 3 antennas, looks just like the 2.0.
I tried flashing it with the 2.0 Firmware openwrt-18.06.1-bcm53xx-tplink-archer-c5-v2-squashfs.bin
But all I get is "Unable to upgrade."
Yes I tried to rename the file to something shorter like openwrt.bin but no cigar.
Anything I can do from here? 
Just out of curiosity, what do you expect after flashing? The wlan cards aren't going to work[1] anyways.
[1] That is a lie, but still not far from reality - it has very basic support in b43, but that is limited to 54 MBit/s and not very stable for LP_PHY, N_PHY and newer chipsets, at least nothing one would buy a new router for.
2 Likes