17 September 2021
One potential reason why WebPAM might be inaccessible from your browser is that it the E610f uses TLS1.0, which is no longer supported by many browsers and indeed many web pages. I'm not sure if this is the case, but it's pretty likely. So the first suggestion is to try another browser, perhaps Firefox or Chrome. I'm pretty sure Firefox will allow you to enable TLS1.0, older versions of Firefox did.
Another potential reason is that there might be damage to the flash drive that holds the firmware. If that's the case, you might try managing the unit from an 'ssh' or 'telnet' login or from the serial port.
A simple test whether the management port is up is to ping 10.0.0.1. If you can't ping it there may be a network issue or the port may be down or there may be no path from the computer used to the E610f.