My bad, sand duping cannot be enabled via the paper YML file. You would need a plugin to get it to be enabled. Here is a plugin you can use: https://dev.bukkit.org/projects/gravity-control
Your server is crashing at startup, send your logs so I know why.
How to get logs:
File Manager
Logs folder
Scroll to bottom
Select latest.log
Download
Upload here
Double-check it's disabled on the website, make sure you saved changes, also try doing /whitelist off in-game, have your friend join, add them to the whitelist, then re-enable it if you wish.
Post your logs here. It is crashing at startup.
How to get logs:
File Manager
Logs folder
Latest.log at the bottom of the folder
Download and post here
Enable it in server.properties (or is it some yml folder?) and make sure it saves there.
1.12.2 with mods can be dodgy, so stuff like this is bound to happen.
Post your logs here. It is crashing at startup.
How to get logs:
File Manager
Logs folder
Latest.log at the bottom of the folder
Download and post here
That's an encryped file.. You don't need to access any encrypted files to set up your port.
Follow this guide:
Yes, it's votifier NOT simple voice chat, but you can still follow the guide in there on how to set up a port. Just use the port for Simple voice chat instead.
I recommend opening a support ticket about that, it's probably something to do with worlds that changed from 1.18 to 1.20, but support can actually access your server and help you out better.
https://support.minehut.com/hc/en-us/requests/new
It looks like a Skript issue. Try disabling all your Skripts and see if your server still crashes.
Providing the full, entire log would also be helpful.
Never download plugins from untrusted sources.
If you got an auto-response in your email when you submitted the ticket it'll only be a matter of time now before it's answered, so be patient.
Post moved to Help category (be sure to post support-related posts in the proper Help category).