HT-M02_V2 Blocked after upgrade and reboot

Hello,

I try to upgrade my lor gateway MT-H02_V2 using this command:
rm -rf update_M02* && wget http://minerback.heltec.cn/download/update_M02.sh && chmod +x update_M02.sh && ./update_M02.sh
I add an error message : cp: cannot create regular file ‘/root/.func/watchdog’: Text file busy
I delete the file and redo the upgrade ==> all seems good.
I did a reboot and now my gateway is no more visible on my ethernet network …
How could I restore the system or reinstall or any clue ?

Thanks

This link has the method of updating the firmware and the download of the relevant firmware. Please download the most suitable firmware according to the manual:
https://resource.heltec.cn/download/HT-M02/firmware