Your Necesse server will not start

When a Necesse server will not start on PlayNHost after you edited cfg/server.cfg by hand, a broken line in that file is the most likely cause: Necesse's format separates settings with commas, and a missing one stops the server. Fix the line, or restore the file from a backup, and start again.

Work through the causes

1. A broken line in cfg/server.cfg. Open Files, then cfg, and open server.cfg. Compare the line you changed with the lines around it: the settings sit inside a block that opens with SERVER and { and closes with }, each setting is key=value followed by a comma (on a new server the last line, MOTD, has none), and a comment starts with //. Put back any missing comma or brace. To avoid this, change the file with the panel's editor, which refuses values that would break it: How to change the server.cfg settings of your Necesse server.
2. A mod. If the server stopped starting after you added a mod, move its .jar out of mods (or delete it) and start again: How to add mods to your Necesse server.
3. A new world is still being made. A first start with a new Save Name takes longer while Necesse generates the world. Watch the Console for a few minutes before you restart.
4. Memory. Check the Usage card on the Overview page. If memory sits at your plan's limit when the server stops, remove mods and see How much RAM does a Necesse server need?.
5. The install did not finish. The panel then says "This server’s installation did not finish, so it has not been set up and most actions are unavailable." Open a ticket.

A good start ends with Type help for list of commands. and the badge Online.

How do I restore only the settings file?

Restore a backup taken before the edit: How to restore only some files or one area of your map from a backup. Or download the backup, take cfg/server.cfg out of it and upload it to the cfg folder.

What should I send support?

The last 50 to 100 lines of the Console from the failed start, and what you changed right before it. See What to include in a ticket for each kind of problem and How to fix a server that will not start.