Why can I not access the admin page on my NAS?

try any other browser... Moilla etc.

Did you use: http: in stead of https:?

I tried both IE and Firefox, with the same result.

Be sure you are going in on the correct port.  Some such devices require the use of port 88, port 8080, port 8008 ... etc. instead of the standard port 80.

And as mentioned avoid the use of HTTPS, which defaults to port 443 and is probably not supported on such a device.

I used both http and https.

check the following link it's a useful link

https://community.netgear.com/t5/Using-your-ReadyNAS-in-Business/ReadyNAS-NV-v2-connection-refused/m-p/1345125#M134922

all the best

NAS's  mostly do support HTTPS, allas they also mostly use self signed certificates generated during setup of such a thing.

None of these solutions worked.   Is there some way to reset the NAS to factory default without losing data?

1) read this first.   And No it will wipe your data...
https://kb.netgear.com/20898/ReadyNAS-ReadyDATA-Boot-Menu

Maybe you can gain access through tech support menu.... fixing the service config file as hinted above.
(i have no way to know how to use that) ... the forum in the above link may help.


Otherwise label the disks so you can put them back in the right slots. (disk 1 - slot 1... ) later.
Remove the data disks
Insert a disk that can be wiped and do factory reset... (then you can verify the hardware is still ok)...  the bad config is on the disks though.
Reinserting the original disks & booting the machine will return to the same issue though.

This may help to gain access to your NAS: https://superuser.com/questions/459630/fixing-broken-ssh-on-nas-server

Try telnetting into it on port 80 using the old "I am a browser, tell me about yourself" trick.  See what it has to say for itself.

https://www.the-art-of-web.com/system/telnet-http11/

If the connection is still refused, then I'd start to wonder (a) if there is something else on the network firewalling it or (b) if it has the equivalent of iptables built in, and HTTP is blocked for your LAN's IPs.  (Without knowing the topology of your network, we are forced to speculate.)  In that situation I'd take it off the network, connect it to an old router, plug a laptop into the router, and try again.