Dev Mode, new version WEB UI not work

Hello, set Volumio in DEV Mode.
It was running version 2.246. I updated, I rebooted and the Web UI does not appear but I do see Volumio in Fing. I also see it via ssh.
There is some way to make the Web UI work.
How can I go back to the previous version from ssh?

You can do a factory reset from the command line by creating a blank file in ‘/boot’ called ‘factory_reset’ and reboot. This can be done either by using ‘nano’ the file editor (as ‘sudo’) or by:

sudo echo >  /boot/factory_reset