@ferogot @wimpie007 it's not possible to use these scripts when your router not running official firmware! owners of R3GV2 be aware before you flash openwrt you need to create a full backup from flash chip. then change the bootloader of your router after you change bootloader you can install any firmware you want and it is possible going back to stock firmware.
Also here is the updated scripts :
what's new:
5.start_download_openwrt.bat==> script will download latest snapshot into firmwares folder.
9.start_restore_backup.bat ==> rewrites the entire flash from data / backup.bin, including the bootloader and special sections.
older version with detailed guide is here: