@Akkum 

Hi,

What is the region code of your Archer C50 V4?

Edit: I just noticed you already mentioned it's "EU". There is more than one firmware listed here https://www.tp-link.com/en/support/download/archer-c50/v4/#Firmware . Have you already tried them all?

  @woozle i tried but all versions are not working and not supporting to my router and when I turn on my router it's showing only 2 led one the power and the second the lock one 

Need help 

  @woozle is there any software to flash my router?

  @Akkum 

Perhaps go through this thread: https://forum.openwrt.org/t/restoring-stock-firmware-for-archer-c50-v4/63773

  @woozle ok thank-you 

One more thing I want to ask 

Now I am trying to flash with tftpd but my router is accepting the tftpd any solution 

  @Akkum 

There are TFTP guides for TP-Link routers on Youtube. You might want to check there.

By the way, he computer running tftdp must have a static IP address of 192.168.0.66

  @woozle i checked on youtube tried that ip address but flash is not installing ok my router 

  @woozle and im am doing in PC 

  @Akkum 

This https://www.youtube.com/watch?v=FKZD_2V1sMc is the most detailed guide I have seen.

Note that it only covers the TFTP part. You will still need a firmware *.bin file that has some parts of it cut away. (like someone provided for download in the other OpenWrt forum)