You opened the settings card, changed the difficulty, hit save, saw a confirmation — and in game the mobs are still exactly as friendly as they were. Nothing failed. This page is about what the save actually did, why the running server did not care, and what each field on the card is really for.
Why the change did not take: a running server never re-reads its settings
A Minecraft server reads server.properties once, when it starts. Everything after that runs from memory. That is Minecraft's own behaviour, not something the hosting adds.
What uniz.host adds on top is a deliberate promise: your server's container is never recreated behind your back. When you save, the new configuration is written to your server's record and pushed onto the pod template right away — but the platform explicitly tells Kubernetes not to roll the running pod for it. The consequence is exactly the one you noticed: the setting is saved, and the world you are standing in still has the old value.
The card says so under the save button — "Saving updates this server's setup right away, but it won't interrupt it while it's running. Restart the server (see the Restart button above) to apply the changes." — and if the server was running or starting when you saved, an amber "Changes pending a restart" banner appears at the top of the server page with the line "Changes to mods or settings take effect after the next restart." That banner is the whole signal. It is not a warning that something went wrong; it is a receipt.
Two edge cases worth knowing. If the server was stopped when you saved, no banner appears at all — there is nothing to be out of date, and the change is already in place for the next start. And if your server is crash-looping, Restart is unavailable (it only works on a server that is actually running); stop it and start it again instead, which applies the pending changes the same way.
The one exception: gamerules are instant
Everything on the settings card waits for a restart. Gamerules do not. keepInventory, doDaylightCycle, mobGriefing and the rest are sent straight into the live server over RCON, which is why that card only offers controls while the server is running, and why those values are not stored in our database at all — they live inside the world file. They have their own page: Minecraft gamerules.
The other live-applying group is the sleep block — the auto-sleep window, the asleep MOTD, the wake message and the wake allowlist. Those are configured on the router that sits in front of your server rather than inside the server, so they update without touching the running world.
How to change a setting so it actually takes effect
Open the settings tab for your server
Go to /dashboard/servers, open the server, and pick the settings tab. The Minecraft card is titled "Server properties". You need to be the owner, or a team member the owner granted the settings permission — without it the fields render read-only.
Change the field you came for
Named fields sit at the top of the card; the numeric and on/off fields sit below in four collapsible groups — Gameplay, World, Players and Performance. Enum fields carry a "Server default" option, which is not a value: picking it removes your override entirely and hands the field back to the server image's own default.
Save, and watch for the pending-restart banner
Hit "Save settings". You should get a "Properties saved" toast, and — if the server is running or starting — the pending-restart banner at the top of the page. Only the fields you actually touched are sent; everything else keeps whatever it had.
Restart the server to apply it
Use the "Restart" action on the server page. Players online are disconnected briefly and the world is saved before shutdown. The banner clears once the server comes back on the new configuration.
Confirm the change actually landed
Do not trust the form; check the result. Difficulty, game mode and PvP are visible in game within seconds of joining. The MOTD, the icon, max players and the hidden-players setting show on the multiplayer list without joining. If the change is not there after a restart, the console tab is the place to look — a server that failed to boot never applied anything.
What each field really changes
MOTD is the message under your server's name in the multiplayer list, and it is two independent lines of up to 60 characters each. § colour and style codes work in it. Leave it blank and the server image writes its own default line. On Bedrock there is one line only, and it replaces the server name in the list rather than sitting under it.
Difficulty and game mode are the two most-changed fields on the card. Game mode sets what new players join as — it does not retroactively convert players who have already been on the server, unless you also switch on force gamemode on join in the Players group.
World seed and world type are the fields that surprise people most: they affect newly generated chunks only. The terrain already on disk was generated with the old values and is not touched, so changing them alters what you find when you walk into unexplored land, not the base you already built. Both are Java-only.
View distance and simulation distance are separate knobs that people routinely confuse. View distance is how far the world is sent to the client — it is what players see. Simulation distance is how far from a player the world stays active: mobs move, crops grow, redstone runs. Lowering simulation distance is the cheaper of the two for performance, because it reduces work rather than just what is drawn. Both accept 3–32 on Java. On Bedrock, simulation distance is called tick distance and only accepts 4–12, so we clamp your value into that range before it reaches the server.
Max players (1–200) is a cap on concurrent connections and nothing else — raising it does not give your plan more RAM, and a number your plan cannot feed just turns "server full" into lag. Pick it against the RAM you actually bought; has the numbers.
Spawn protection is the radius in blocks around world spawn where non-operators cannot build or break. 0 to 64, and see the defaults section below before comparing it against a guide from elsewhere.
Online mode verifies every joining player against their Mojang/Microsoft account. Turning it off is the single riskiest control on this card, and the card raises a "Security risk" alert when you do: the server stops checking accounts entirely, so anyone can join under any username — including your own, or an operator's. Anyone who can reach the address can then claim operator identity. If you have a reason to turn it off, the whitelist stops being optional.
Whitelist is a switch, not a list. Turning it on means only players you have added can join; it does not add anyone. The names themselves live in the Players tab, which reads and writes the server's whitelist file — and works whether the server is running or stopped. A whitelist switched on with an empty list locks everyone out, including you.
JVM performance flags are two switches over one setting: Aikar's flags, the long-standing garbage-collection tuning most servers run, and MeowIce's, a newer set tuned for Java 17 and up. They are mutually exclusive by construction — turning one on turns the other off, and there is no way to end up with both. Both are ready-made presets; you never hand-write JVM arguments here. Which Java version the server boots on is a separate field, covered in .
The server icon is the one field that takes three stages, not two. Pick an image and crop it square: it uploads immediately and the card shows "Icon uploaded — save to apply". Then save the card, which stores it against your server. Then restart, which is when the world's icon file is actually replaced. Removing the icon in the card only clears the field — the last icon your world was given stays until a new one replaces it. Java only; the Bedrock server has no server-icon file.
Two defaults here that differ from vanilla
If you compare the card against a Minecraft guide written for a hand-built server, two values will not match, and both are on purpose:
| Setting | On a server created here | Vanilla |
|---|
| Spawn protection | 0 — nothing around spawn is locked | 16 blocks |
| Hide online players | on — names and count hidden on the list ping | off |
These are seeded when the server is created, so a Java server made on uniz.host starts with them. Older servers whose owner never saved settings keep whatever they had; save the card once and the current values are written through.
The numeric and toggle fields on this card have no "reset to default" button, and every other game on the platform has one. That is a deliberate exception rather than a gap: saving a Minecraft setting sends only the fields you changed, and that mechanism has no way to express "delete this one back to the image default" for those particular fields. A reset button there would look like it worked and quietly do nothing on any value you had previously saved — worse than not offering it. The named enum fields at the top of the card do have the honest version of it: choosing "Server default" genuinely removes the override.
Read next
- — the settings that do apply instantly
- — which JVM your server boots on, and how Auto picks it
- — what max players and view distance actually cost you
- — reading the rest of the server page