> ## Documentation Index
> Fetch the complete documentation index at: https://perplayerkit.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Startup and database problems

> The plugin will not load, database errors on startup, and missing kit shortcut commands.

## The plugin will not load

Check the <Tooltip tip="The text window or log where your server prints what it is doing.">console</Tooltip> for the real error.

* **Server version.** Paper or Spigot **1.19 or newer**.
* **Java version.** **17 or newer**. Verify with `java -version` on the host, not the control panel.

<Tooltip tip="The error Java prints when a jar was built for a newer Java than the one running.">`UnsupportedClassVersionError`</Tooltip> means Java is too old.

## Database errors on startup

| Check               |                                                                                                      |
| ------------------- | ---------------------------------------------------------------------------------------------------- |
| Storage type        | No database server? Use `storage.type: "sqlite"`.                                                    |
| The database exists | MySQL and PostgreSQL: the database must **already exist**. The plugin creates tables, not databases. |
| Credentials         | Username, password, and host.                                                                        |
| Port reachable      | Remote database: `3306` MySQL, `5432` PostgreSQL, `6379` Redis.                                      |
| Pool size           | Connection-wait timeouts under load mean `maximum-pool-size` is too low.                             |

See [Storage and databases](/settings/storage).

## /k10 and above do not exist

Slots above 9 need [`kits.max-slots`](/features/kits) raised, and register only at startup. **Full restart** required; a <Tooltip tip="Reloading re-reads plugins without stopping the server. Some things only take effect on a full restart.">reload</Tooltip> will not do.

## Config migration failed

Fix the file or folder named in the console error, then restart. The original config remains in place; backups are beside it.

## Kit data is still loading

Wait for the database read to finish. If the plugin says data is unavailable, fix the storage error and rejoin. Editing stays blocked to protect existing kits.

## A kit save failed

The console reports the storage error. Failed writes are retried after a successful connection check. If shutdown still has failed writes, it retains them in `failed-kit-writes-<time>.yml` in the plugin folder. Keep that file with your database backup and ask for help before switching backends.

See [Backups](/data/backups) and [Upgrading](/upgrading).