This guide will help you with Hytale Startup Failure: Missing Server Session Token and Auth Grant Error.
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Startup failures in Hytale that reference a Missing Server Session Token or an Auth Grant Error typically indicate that the game client is unable to complete its authentication handshake with the server. These errors often appear during login or immediately on launch, and they prevent the game from establishing a valid session needed to load player data and connect to online services. While the messages can look technical or intimidating, they usually stem from a handful of common causes such as corrupted cache files, expired credentials, network restrictions, or mismatched launcher configurations. Understanding why these authentication failures occur makes it much easier to resolve them. The following guide breaks down what triggers these errors, how they affect the startup process, and the most reliable steps to restore a valid session so the game can launch normally.
Overview
When launching a Hytale server, you may encounter a message in the console that looks similar to the following:
Server session token not available – cannot request auth grant
When this issue appears, the server technically completes its startup sequence, but it immediately blocks every incoming player connection. The root cause is that the server has not authenticated against a valid Hytale account, so it cannot obtain the server session token required to verify and accept players.
This guide explains the reason behind the error and provides step‑by‑step instructions for fixing it through Hytale’s device authentication workflow.
Symptoms
A typical console output for this issue resembles the following:
Server authentication unavailable - please try again later
Until that token is issued, every join attempt is automatically rejected, leaving the server running but effectively inaccessible.
Post Mortem ( The Cause\Issue )
Hytale servers must successfully authenticate with a valid Hytale account before they can generate the server session token that enables secure player connections. When this authentication step hasn’t been completed or when previously stored credentials are missing or invalid, the server is unable to produce the token required to request an authentication grant.
This error appears when either of the following is true:
The server has never been authenticated.
The server was authenticated previously, but the credentials were not saved and were lost after a restart.
Without that grant, the server starts in an unauthenticated state and cannot validate or accept any incoming player sessions.
Most commercial game‑server providers, including platforms like CitadelServers.com, complete the authentication process automatically in the background, so customers never have to interact with device login or credential management. When you’re running your own self‑hosted instance, however, this automation isn’t present. You must complete the authentication step manually so the server can generate its session token and operate in a fully authenticated state.
Solution: Authenticate the Server
Step 1: Start the Server
Log in to your Citadel Servers Game Control Panel and open your Hytale service to begin the authentication process.
Start your Hytale server as you normally would and allow it to complete its full startup sequence.
At this stage, you may already see the authentication error appear in the console. This is normal and simply indicates that the server has not yet been linked to a valid Hytale account.
Step 2: Run the Device Login Command
In the server console, enter the following command to generate a new device‑authentication request:
This code is unique to your server instance and is required to link the server to your Hytale account during the device‑authorization process.
Step 3: Authorise via Browser
Open the verification URL shown in the console and sign in with your Hytale account. If prompted, enter the device code provided by your server and approve the authorization request to complete the login.
Once the authorization is confirmed, the server will automatically finish its authentication sequence. At that point, you should see console log entries similar to the following, indicating that a valid session token has been issued and the server is now fully authenticated:
Step 4: Persist Authentication (Required)
To ensure authentication persists across server restarts, run the following command in the console:
Loaded encrypted credentials from auth.enc
Verification
You can check the server’s current authentication state at any time by running:
Want a Trouble-Free Setup?
If you prefer to avoid manual authentication, command‑line setup, and hands‑on server management, you can choose a fully managed Hytale server from LOW.MS instead.
With LOW.MS:
Server authentication is handled automatically
Credentials are securely persisted for you
Servers come preconfigured and ready to join
No manual console commands are required
This is the most convenient option if you want a reliable, low‑maintenance Hytale server without handling setup tasks or dealing with future authentication changes.
Summary
| Step | Action |
|---|---|
| 1 | Start the server |
| 2 | Run /auth login device |
| 3 | Authorise in browser |
| 4 | Run /auth persistence Encrypted |
| 5 | Restart safely |
Still Seeing the Error?
If the error continues to appear, work through the following checks:
Confirm that the Hytale account login and device authorization completed successfully
Ensure the server has outbound internet access for authentication requests
Verify that auth.enc exists in the server directory and is writable
Restart the server after enabling credential persistence
If the issue persists, contact our support team and include your full server startup logs so we can investigate further.
Please click here to contact our support via a ticket.
