Loboto Chan @LCHAN

The Opensimulator package on the website is outdated. I recommend grabbing the one from OSgrid and using that. It will take a little more work to configure (especially if you want to host your own grid), but you will get all the latest features as a reward for your effort (without having to compile from source).

You can technically configure an opensim server in such a way that you can connect locally AND remotely behind a loopback router... but it... is not ideal. If you configure the User Server (Robust) to run on a domain name (or free subdomain) and your region to run on static IPs, it works.

The local computer can connect by adding the server's lan ip to the grid manager in Singularity (This trick doesnt work in Firestorm).
The host computer must have the server's public IP in it's hosts file.

This configuration causes 3 major problems:
-You MUST use singularity.
-It breaks hypergrid connections (you cant return after teleporting out)
-Firefox has severe issues with reading and editing parcel information including windlight settings.

You will recieve an error in the console reading
"[LAND MANAGEMENT MODULE]: Unable to find parcelID -1"

Technically you can connect to a local server while having it configured for external use behind a NAT... but the only way to reliably do this is by using a VPN. Not all VPN configurations work, allow you to circumvent the NAT. ProtonVPN and Privado work. Windscribe worked as long as you do not use split tunnel.

VOIP:
Unfortunately not much luck with freeswitch. From what I hear Vivox is being retired in favor of webrtc. The mumble solution requires modification of viewer code.
Freeswitch almost works for me. Users can be seen in local voice chat. The call is never started tho.
I am unsure if this is related to the 'proxy authentication' error i saw.

Getting help in this community is like pulling teeth, I swear to god.
Anyway. Windlight settings.
Noone seemed to have any answers, so I am sharing what I know.

Officially, opensim discontinued Windlight.
http://opensimulator.org/wiki/LightShare
You can still enable those settings in OSSL and OSSLDEFAULT config files. You used to have to enable them in Xengine settings but Yengine doesnt seem to require it.

The default settings that come bundled with Firestorm, Singularity, and Coolviewer are buggy AT BEST.

Region weather settings are saved to whatever database you are using in your server in a kind of strange, sloppy way. It isn't 1:1 with SL Windlight settings.
You're actually better off editing region windlight settings with a script than attempting to change them with the viewer.
https://www.outworldz.com/cgi/freescripts.plx?ID=1122

You can edit this script to get the job done. If you are using Windlight i really recommend using the singularity viewer- it seems to play nice with Windlight.

Also, after hitting an option to change the windlight settings... hit 'world', 'region/estate'. For whatever reason this triggers a refresh of the windlight settings on the region and you can see the changes you've made.

In case anyone was wondering about that troll 'boxcleaner'...
do not trust a word they say. They admit as much themselves:
(the following is their morse code messages translated)

THE IMPACT OF TROLLING IS UNDENIABLE. IT CAN SILENCE VALUABLE VOICES, PARTICULARLY THM
THE TROLL'S ARSENAL IS VAST. THEY MAY DEPLOY INFLAMMATORY REMARKS, BLATANT LIES, OR HE
IN THE DIGITAL AGE, THE ONCE-MYTHICAL TROLL HAS LUMBERED OUT OF FOLKLORE AND INTO THE COT
AS WE DELVE DEEPER, THE LAYERS SHIFT, REVEALING MORE SUBSTANTIAL KEEPSAKES. A CHIPPED PO

The important bit is that they glorify being a blatant liar. Basically, you can't trust them at all.

Has your default SL viewer been hijacked?
Well, you can fix that in regedit.
There are three or four entries you'll need to change, one per protocol.
Viewer name isnt really important, its mostly cosmetic.

>HOP:
VIEWER NAME: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\hop\shell\open - FriendlyAppName
APPLICATION LOCATION: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\hop\shell\open\command - Default

>Secondlife:
VIEWER NAME: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\secondlife\shell\open - FriendlyAppName
APPLICATION LOCATION: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\secondlife\shell\open\command - Default

>X-grid-info:
VIEWER NAME: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\x-grid-info\shell\open - FriendlyAppName
APPLICATION LOCATION: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\x-grid-info\shell\open\command - Default

>X-grid-location-info:
VIEWER NAME: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\x-grid-location-info\shell\open - FriendlyAppName
APPLICATION LOCATION: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\x-grid-location-info\shell\open\command - Default

Format of the 'default' link registry key is always:
"C:\Program Files\Singularity\SingularityViewer.exe" -url "%1"
%1 is always replaced with the url you are choosing to open

Today there is way too much drama in the box. I was looking for grid help, or conversation. So. If you want to remove "the box"... use greasemonkey/tampermonkey. Create a script for this site. Add...
// @require https://code.jquery.com/jquery-3.6.0.min.js
under 'grant' at the top.
THEN. add this:
(function() {
'use strict';

$( '.panel-heading:contains(" The Box ")' ).parent().remove();

})();