FAQs, and Common Issues and Fixes

Here you can find frequently asked questions, and fixes to commonly encountered issues.

Errors "Failed to login - null" or "Failed to login - invalid session" when joining a server

Issue Description

These errors mostly happen when there is a Microsoft account authentication issue on your launcher, whether it is Technic or CurseForge.

 

Authentication error example 1 Authentication error example 2

 

Solution(s)

1. Closing the game and launcher completely, logging out from the launcher, and relogging back in are the most common fixes.

2. If that still doesn't work, you can navigate to %appdata%/roaming/.technic and delete the oauth folder.

If this still doesn't resolve the issue, you can open a support ticket on our Discord server.

Updating Java 8

Recently, Mojang changed its authentication system. Players using Java 8 versions older than Update 91 can no longer log in to Minecraft servers, including ours. To resolve this issue, update Java 8 on your computer.

 

Step 1: Uninstall Your Existing Java 8 Version

CurseForge users may not have an existing Java 8 version installed. If not, skip to Step 2.

Older Java 8 versions lack critical security fixes and must be removed before installing the new version.

  1. Open Settings → Apps → Installed Apps.
  2. Search for Java 8 in the list.
  3. Select it and press Uninstall.
  4. Follow the confirmation prompts until it's entirely removed.

Uninstall Java 8

 

Step 2: Install the Latest Version of Java 8

This guide covers installing Oracle Java. Other Java binaries also exist from organisations such as Adoptium and Amazon, which can also be used.
  1. Go to the official Java download page: Java 8 Manual Downloads.
  2. Under Windows, choose Java 8 (Offline 64-bit) and download the installer.
  3. Once downloaded, run the installer and follow the on-screen instructions.

Java 8 download page

Following this, you should have the latest Java 8 installed.

If you have other versions of Java installed, you may need to uninstall them or select the correct Java version in the relevant launcher settings.

 

Step 3: (CurseForge Only) Update Java Path in CurseForge Launcher

If you use the CurseForge launcher, you may need to change the Java path to point to the correct Java version.

  1. Open the CurseForge launcher.
  2. Select the settings cog on the bottom left of the launcher.
  3. Select Minecraft and scroll down to Java Versions.
    CurseForge Java Versions setting
  4. Select Choose.
  5. Type C:\Program Files\Java\jre1.8.0_461\bin as the file name and press Enter.
    Java path in file browser
  6. Select java.exe.
    Select java.exe

The file location may differ on certain systems. Contact staff if you are unable to find java.exe.

After this you should be able to join our servers using the CurseForge launcher.

Machines Not Breaking Blocks Inside of Claims

Step 1: Verify the Machine's Setup

  1. Redstone Control
    • Ignore: The machine operates without a redstone signal.
    • Low: The machine runs when it receives a low redstone signal.
    • High: The machine runs only when it receives a strong redstone signal.
    • Pulse: The machine operates only when it receives redstone pulses.
  2. Orientation: Confirm the machine is facing the correct work area.
  3. Range Upgrades: Check that any required range upgrades are installed.
  4. Power: Ensure the machine has sufficient power.
  5. Output Inventory: Verify there is enough space for output items, if applicable.
  6. Input Inventory: Verify there are sufficient input items, if applicable.

 

Still Not Working? Check Claim Permissions

If the machine still isn't working after completing the setup checks, it may not have permission to break blocks inside your claim.

  1. Stand inside your claim and run /autotrust
    Automatically trusts any block-breaking action for 30 seconds.
  2. Power on and activate the machine.
  3. The machine should now function correctly within your claim.

If the server you are on uses mods with "fake players", such as Just Dire Things, you can trust them manually using /trust <fake_player_name>. For example, the fake player name for Industrial Foregoing is #[IF].

Claim Expiry / Regeneration on SiriusMC

FAQ - Claim Expiry / Regeneration

Q: How long do I have to be inactive before my claims are subject to regeneration?

120 days. Inactivity is tracked network-wide, not per server. So if you haven't logged into RLCraft for 120 days but have been active on ATM10, your RLCraft claims are still protected and cannot be regenerated regardless of any requests made.

Q: I want to claim somewhere, but someone who was last online 200 days ago has already claimed nearby. Can I get their claim removed?

Yes. If a player has been inactive across the entire network for more than 120 days, their claims become eligible for regeneration. To request the removal of someone's claim, you will need to open a support ticket.

Q: When staff clears an inactive claim, will the area be regenerated and does that delete everything?

Yes. When a claim regeneration is requested, any builds, containers, and entities within the claim will be removed.

Claim regeneration is never automatic - it only occurs when another player specifically requests it.

What Are Banned Items on SiriusMC?

FAQ - Banned Items

Q: Why is <item> banned?

SiriusMC optimises gameplay for our players, and some more destructive items are banned. These items are banned due to their potential to harm server performance or the economy, or because they may be used to destroy claimed player bases.

Q: How do I know what items are banned?

 Use /banneditems in-game to see the full list.

Q: What should I do if I think an item should be banned?

If you notice items or mods causing dupe glitches, claim bypassing, or imbalanced gameplay, please create a ticket on our Discord server.

How Much RAM Should I Allocate?

FAQ - How Much RAM Should I Allocate?

Q: How much RAM should I allocate to play on a server?

Modded servers often tell you how much RAM is needed for a smooth play through. We've compiled a list of our servers and their RAM recommendations here. However, you can find a compact list below:

Tekkit SMP 3–5 GB recommended
Tekkit 2 3–5 GB recommended

The 1.12.2 Pack

 5–8 GB recommended

RLCraft

 2–5 GB recommended

ATM10 (All The Mods 10)

 8–10 GB recommended

ATM10: To The Sky (ATM10:TTS)

 6–8 GB recommended

 

Q: How do I know if I've not allocated enough RAM?

  1. Rubber-banding: You walk forward, and the game teleports you back to your previous location repeatedly.
  2. Chunks Not Loading: Nothing generating when walking into new areas.
  3. Stuttering and Lag Spikes: The game freezes for ~2 seconds, usually every 30–60 seconds.
  4. Out of Memory Crash: The game crashes entirely, showing an "Out of Memory" or "java.lang.OutOfMemoryError" error.
  5. Slow Inventory/GUI Interaction: Opening chests, crafting tables, or JEI items takes several seconds to load.

Cannot Extract Native Jar | Prism Launcher

Issue Description

When attempting to launch a modpack using Prism Launcher an error in the console states "Cannot Extract Native Jar".

Solution(s)

1. Stopping javaw.exe

    1. Open command prompt as an Admin 
    2. Run tasklist and look for the process javaw.exe
    3. Run taskkill /f /IM javaw.exe 
    4. When it says successful close command prompt and launch the modpack again

2. Linking Your Microsoft Account

    1. Click "Profile" in top right
    2. Select "Manage Accounts"
    3. Select your account
    4. Click add Microsoft
    5. Sign in with your Microsoft account

3. Re-linking Your Microsoft Account

    1. If your account is already linked you can re-link it
    2. Click "Profile" in top right
    3. Select "Manage Accounts"
    4. Right-click your account
    5. Click remove
    6. Click add Microsoft
    7. Sign in with your Microsoft account