Upon a fresh install, the PHP login page will not work despite prior successful tests authenticating to proxmox, spitting out the "Error connecting to Proxmox" error, if your Proxmox web UI is accessed through default port 8006.
This seems to be due to setup.py not adding on the port number at the end of the "proxmox_host" variable.
Line 283:
replace(web_dir+config, params)
Changing "proxmox_host" in config.ini from just the IP to the IP:port of the Proxmox web UI fixed this.
I can submit a PR to fix this later this week