Start a server in safe mode

When a datapack fails to load, a Minecraft Java server stops during startup, and the console shows:

Failed to load datapacks, can't proceed with server load. You can either fix your datapacks or reset to vanilla with --safeMode

Safe mode starts the server once with Minecraft's --safeMode option. The world loads with only the vanilla datapack, so the server comes up and you can fix or remove the datapack that broke it. The Safe mode panel on a server's Software tab adds the option for one start only: the next start after that is a normal one.

• Safe mode works on Minecraft Java 1.16 and newer, with plugin servers such as Paper, with Vanilla and with mod loaders such as Fabric and Forge. Proxies load no datapacks, and Bedrock servers have no safe mode.
• Take a snapshot of the server first. Safe mode also skips the datapacks that were working, and you are about to change the world's files.
• On a server someone shared with you, you need the Install software permission, and the Power permission to start the server from the panel.

1. In the dashboard, go to Container Apps and open the server, then the Software tab.
2. Select Safe mode.
3. Select Start in safe mode.

A running server restarts, and a stopped one starts. The badge on the panel shows Running in safe mode once the server is up.

To choose when the server starts, arm safe mode instead:

1. On the Safe mode panel, select Arm for the next start. The badge shows Armed for next start.
2. Start the server from the console when you are ready, or select Start now on the panel.

To cancel before the server starts, select Disarm safe mode.

While the server runs in safe mode, the panel warns The server is running in safe mode now. Fix or remove the datapack that broke it, then restart normally.

1. Find the datapack that failed. The error lines in the console before the message above name it.
2. Remove it, or replace it with a build that works with your Minecraft version. Datapacks are in the world's datapacks folder, such as world/datapacks. Remove them on the Installed addons panel or in the Files tab.
3. Restart the server from the console.

As soon as the safe-mode start stops, safe mode switches itself off, and the badge shows Off. If you restart without fixing the datapack, it can stop the server again.

The server starts on the vanilla datapack alone, and the console shows the world loading. After the normal restart, the world loads with the datapacks that remain in its folder.

Safe mode is not available here

The server's software cannot use the option. The panel gives the reason, such as Safe mode needs Minecraft 1.16 or newer. or A proxy loads no datapacks, so there is nothing for safe mode to skip. On a Bedrock server, remove the broken pack as Manage Bedrock packs describes.

The panel says Starting in safe mode. but the server does not start

The start was refused, as it is while a free server waits in the queue to wake or while we have locked the server. Safe mode stays armed, so the server uses it the next time it starts. Start it from the console when you can.

The world still does not load in safe mode

Safe mode skips datapacks only. When the console shows another error, such as a broken mod or plugin, remove that instead. Troubleshoot servers lists common causes.

The same error comes back after the normal restart

The broken datapack is still in the world's datapacks folder. Start in safe mode again and remove it.

• Manage installed addons
• Use the console and power controls
• Troubleshoot servers

curl -X POST https://api.coritan.com/api/v1/client/servers/$SERVER/software/safe-mode \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"enabled": true, "start": true}'

The response has state (off, armed or active), armed, active, flag (--safeMode) and synced. With start, started says whether the server started, action says whether we sent start or restart, and start_error gives the reason when the start was refused. Safe mode stays armed after a refused start.

GET /api/v1/client/servers/{uuid}/software/context shows the same state under safe_mode, with supported and unsupported_reason.

Arming on software that cannot use safe mode answers 400 with the reason, and a body without enabled answers 400 with enabled is required. Arming needs software.install, and start also needs control.start.