problem flashing qsdk-12.0-ipq60xx-5.4 image on Mango

[liviolima80]

Hi,
I compiled the branch qsdk-12.0-ipq60xx-5.4 for Mango Dev board. If I flash the board the first time using one of the methods reported in wiki

https://wiki.8devices.com/mango:flash

everything works well and the board restart with the new image. If I try to repeat the process for the second time using the same image, or also a different one (e.g image of old branch) I get the following error:

root@OpenWrt:~# sysupgrade -v -F -c /tmp/openwrt-test.bin
Image metadata not found
Error: mandatory section(s) missing from "/tmp/openwrt-test.bin". Abort...
Image check failed but --force given - will update anyway!
Saving config files...
etc/hosts
[...]
etc/opkg/customfeeds.conf
Commencing upgrade. Closing all shell sessions.
Watchdog handover: fd=3

• watchdog -
  Sending TERM to remaining processes ... netifd rngd wpa_supplicant uhttpd miniupnpd ubusd urngd dnsmasq ntpd logd rpcd sh: S: out of range
  hostapd
  [ 81.060851] device wlan1 left promiscuous mode
  [ 81.060918] br-lan: port 2(wlan1) entered disabled state
  [ 81.181857] device wlan0 left promiscuous mode
  [ 81.181922] br-lan: port 3(wlan0) entered disabled state
  Sending KILL to remaining processes ... sh: S: out of range

Switching to ramdisk...
Performing system upgrade...
Error: Cant' find kernel@1 after switching to ramfs, aborting upgrade!
Error: Cant' find fdt@1 after switching to ramfs, aborting upgrade!
Format: Log Type - Time(microsec) - Message - Optional Info
Log Type: B - Since Boot(Power On Reset), D - Delta, S - Statistic
S - QC_IMAGE_VERSION_STRING=BOOT.XF.0.3-00090-IPQ60xxLZB-2

I get similar error through msg box also if I perform the operation with LuCi web interface

Can you give me some suggestions?

Regards