You won't have any success until you can get JFFS to mount. It's essential for the normal operation of the router. It's also where those reservations are stored on your model.
Try rebooting the router and see if it fixes itself. If it doesn't look in the system log for any relevant error messages.
Failing that I would suggest you backup your current settings and JFFS partition*** (Administration - Restore/Save/Upload Setting), if you have anything worth saving. Then do a Factory Default Restore via the GUI with the "Initialize..." box ticked. Then after the reboot perform only the mandatory setup procedure and check whether JFFS is now mounted. If it is then restore from your previous backup (if required).
*** If your JFFS partition isn't mounted your router will only be partially configured. So it's probably not a good idea to try and backup and restore it anyway. Just do the factory reset.
@ColinTaylor you are my hero! Who would have thought that an update would get so sweaty...
Re-booting did nothing, so the next step was a default factory restore from the GUI as you suggested. Problem was, there appeared to be a disconnect between what the browser said was happening and what the router actually did - it was like some Javascript in the browser was doing it's own thing - drawing it's current reset status - or logging me out, when the router was doing no such thing.
Finally got the router back up and factory reset, but then of course, I couldn't connect to it - on account of the (reset IP settings) - so for anyone else struggling with this:
https://www.netsetman.com/ is your friend - particularly if you are doing per device IP re-configs to point to pi-hole (yes, you can do it by hand, but Windows...).
So it all came up and JFS was back!
Amazingly, restoring from a backup (that I took only yesterday - Phew!) my static IP's were also restored AND I was connected to the internet (don't know what was happening, but typing my ISP login and password via the initial setup (post reset) was having none of it - but I had made a backup that specifically included the password, and all was good).
Finally, the one reason why I updated, was that I have a number (I am going to get a bit weirdy beardy now - sorry) of Sonoff devices flashed with Tasmota. From time to time (it is unpredictable) the devices would randomly drop off the network, and the only way to recover, was to re-flash them, which was a pain. Then, one day, by sheer chance, I discovered that there was nothing wrong with the devices - no need to re-flash. The problem was actually with the 2.4GHz 86U WiFi, in that it presented, but how ever many times the device provided the correct SSID/Password, the 86U would refuse a connection. So at that point, I tested that could connect the device to alternate routers/SSID's, so there was nothing generically wrong with the device/config, just that the 86U wasn't allowing a connection - I guess, on renewal of lease, as devices already connected over 2.4Ghz remained fine.
The *fix* was therefore to power cycle the 86U (pulling out the power cable was the only action that actually worked) and all the devices that couldn't connect, immediately connected again. Obviously, I did a lot of swearing when I realised that I had been doing a lot of re-flashing/reconfig of devices for nothing - and tell this story here, only because the forum is peppered with folk talking about their 86U 2.4Ghz failing and being RMA'd etc. Maybe these things just needed the power pulled out all along? Anyhow, I am interested to see if this update makes a different to this issue?
Thanks again!
