caillou

Hello everyone, I'm trying to upgrade a VTO (3211D) using files from here https://www.ip-phone-forum.de/threads/dahua-vto-vth-firmware-link-sammlung-anleitungen.305121/ My current version is 3.20.9999000.0.R 1st trial try is on this one General_VTO3211D_Eng_P_SIP_V4.300.0000000.5.R.20200323 http://www.mediafire.com/file/xlrdd...11D_Eng_P_SIP_V4.300.0000000.5.R.20200323.zip But I keep getting upgrade fail at 50% Thanks to the advice I found on this topic: I tried with congiftool5.0 or VDPconfig or configtool 3.2 I tried with the zip file that I renamed .zip.bin, or the main .bin file inside the .zip I tried to change port tcp 37777 to 3800 with the web service but after reboot, VTO goes back to 37777, not sure why. I didn't see how to change port from configtool I tried older firmwares also But it keeps failing What am I missing ?