Update Phc2Mqtt to v5 via Webinstaller does not work

Hello everyone,

Background: I want to connect my PHC system to Home Assistant during the Christmas holidays. The idea is to use Home Assistant via IOBroker and Phc2Mqtt hardware to control the house. Important for setup: Home Assistant runs on its own VM, IOBroker on another separate VM under Ubuntu Linux. 
I started setting up the Phc2Mqtt hardware. I receive the MQTT data in IOBroker. Writing MQTT data does not work in IOBroker for now.
End of background story I solve this later.

I decided to flash the Pch2Mqtt hardware to the current version.
To do this, I unscrewed the case and connected the ESP32 to the PC via USB.
I installed the UART driver:
www.silabs.com/software-and-tools/usb-to...rivers?tab=downloads
and used the web installer ( sim0njo.github.io/install/ ) in EDGE and Chrome.
Unfortunately, I got the same error message every time:

“Failed to download manifest”
 
 

Find a workaround:
I load the v5 ther sim0njo.github.io/docs/Downloads/ and insall it with the webinterface.

Was not the best idea, after a powercycle I could not reach the device any more....

@simon, coul you help me to flash the ESP32 ?