Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallIf an RLCraft server will not start, check the Java runtime first: RLCraft 2.9.3 for Minecraft 1.12.2 requires Java 8. Java 17 and Java 21 are commonly reported to fail during boot, sometimes with the message AppClassLoader cannot be cast to class java.net.URLClassLoader. After Java, verify Forge 14.23.5.2860 (Forge 2860), make sure every client and the server use RLCraft 2.9.3, and then work through the crash log before changing mods.
Godlike.Host offers modded Minecraft server hosting with one-click modpacks, a built-in mod installer and up to three free backups a day.
This guide separates startup crashes from client crashes, world-generation freezes, and connection failures. Back up the server folder and world before each change so you can undo a bad update.
As an Amazon Associate I earn from qualifying purchases.
Free tools Windows power users keep installed
One-click scans. No signup required.
Check the baseline before troubleshooting
RLCraft is not a plug-and-play server jar. The 2.9.3 release is built for Minecraft 1.12.2 and its expected Forge loader is 14.23.5.2860. A mismatch in any one of those three versions can look like a random crash or a failed connection.
| Item | Required baseline for RLCraft 2.9.3 | What a mismatch looks like |
|---|---|---|
| Game version | Minecraft 1.12.2 | Missing-mod errors, handshake rejection, or an incompatible client |
| Modpack release | RLCraft 2.9.3 | Players are kicked during login or see a mod-list mismatch |
| Forge | 14.23.5.2860 (Forge 2860) | Loader errors, failed dependency checks, or an immediate exit |
| Java | Java 8 | Startup failure, class-loader errors, or a crash before the console finishes loading |
Do not assume that a newer Java installation is automatically better. RLCraft 2.9.3 depends on the older 1.12.2 modding ecosystem, and current Java runtimes can be incompatible with it.
#1 Best Overall
- BLUE LIGHT BLOCKING GLASSES: Our blue light glasses for women boast UV400 protection, blocking harmful blue rays from computer screens. With these bluelight glasses women, you can enjoy gaming, reading, or watching TV with no worries of eye strain.
- EYE RELIEF: Our blue light glasses are engineered to reduce blurry vision or strain caused by prolonged screen time. These womens blue light glasses aid in better sleep by preventing blue light from disrupting your natural sleep cycle, helping you fall asleep faster and enjoy a more restful night's sleep, making them the perfect christmas present.
- COMFORTABLE: Crafted from durable material, our trendy blue light glasses for woman or blue light glasses men ensure long-lasting comfort. The high-transmittance lenses accessories, gamer gifts for men, help keep your eyes relaxed. Perfect stocking stuffers, gifts for gamers men, christmas gifts for men, halloween costumes.
- LIGHTWEIGHT: These clear blue light glasses feature a lightweight frame, meaning they’ll stay comfy for long-term wear. Perfect as blue blockers glasses for women or mens blue light glasses, these non-prescription fake glasses for men can be worn throughout the day. The blue light blocking glasses women feature polycarbonate HD lenses, which are anti-reflective and restore true color.
- WORRY-FREE PURCHASE: If you experience any issues, our support team is ready to assist you quickly. These are the perfect costume glasses for cosplay dressing up.
1. Fix the Java version first
Java is the highest-probability cause of an RLCraft server that never reaches the “Done” state. Hosting guides published in 2026 report that Java 17 and Java 21 fail on boot, while Java 8 is the supported runtime for this pack.
Confirm which Java the server actually uses
Run the version command from the same account, control-panel runtime, or startup script that launches the server:
java -versionThe output should identify a 1.8 release, usually displayed as 1.8.0_xxx. If it reports 17, 21, or another major version, installing Java 8 is not enough by itself: the server must be pointed at the Java 8 executable.
Point the launch command at Java 8
On a managed host, select Java 8 in the server’s runtime or startup settings. On a self-hosted machine, replace the generic java command in the start script with the full path to the Java 8 executable. Keeping newer Java versions installed is fine as long as this server uses Java 8.
A typical Forge launch command is:
java -jar forge-1.12.2-14.23.5.2860.jar noguiYour generated Forge filename may differ; use the jar created by the Forge 2860 installer rather than inventing a new name. Verify the runtime again from the server console after editing the script.
Rank #2
- WINDEX GAMING WIPES: effortlessly clean all your gaming gear and gaming electronics in one easy step with our new Windex Gaming Wipes
- AMMONIA FREE: our ammonia-free formula is safe to use on all of your favorite gaming equipment like consoles, headsets, controllers, screens, keyboards, and more
- PRE-MOISTENED WIPES: each wipe instantly removes dust, dirt, and stubborn smudges and fingerprints leaving a streak-free shine
- ANTI-STATIC: great for cleaning and wiping down your gaming gear and electronics leaving behind no visible residue
- COMPACT RESEALABLE PACKAGE: store your pack of Windex Gaming Wipes anywhere in your home for whenever a quick and easy wipedown is needed
Recognize the class-loader symptom
The message AppClassLoader cannot be cast to class java.net.URLClassLoader is widely associated with running an older Forge-based pack on a Java version newer than Java 8. Switch the runtime before removing mods or deleting world files.
One older Forge forum report found that Java 8 build jre1.8.0_199 worked while jre1.8.0_261 did not. That is a single, low-confidence report rather than a compatibility rule. If Java 8 still fails, test a different Java 8 distribution or update, but preserve the crash log and change only one variable at a time.
2. Verify Forge 2860 and the pack release
RLCraft v2.9 is listed as requiring Forge 2860, and RLCraft 2.9.3 is the release this troubleshooting sequence targets. Check the server’s startup log for the Forge version and check the installed profile on every player’s computer.
- Stop the server completely; do not replace files while Java is still running.
- Confirm that the server is using Minecraft 1.12.2.
- Confirm that the Forge loader is 14.23.5.2860.
- Confirm that the server and every player are on RLCraft 2.9.3, not 2.9.2d or a 2.8.x build.
- Start the server without making any other mod or configuration change.
A client with a different release can be rejected even when the server itself starts normally. Do not copy a newer client’s mods folder onto the server to “make the versions match”; restore the exact pack files instead.
3. Read the crash log before changing anything else
The first useful error is usually near the bottom of the latest crash report or server log, while the cause may be several lines above it. Save the complete file before restarting so a second attempt does not overwrite the evidence.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Rank #3
- Ergonomic & Adjustable Design: Fight "text neck" and improve your posture. Designed for comfort, it offers an adjustable height (7.1in-8.5in) (1.4in adjustable range) and angle (5°-85°) Please note: cell phone stand is only 9 inches tall—the length of a standard pencil
- Without blocking subtitles Perfect for office desk Tiktok Face Time Zoom video—this is the ultimate kitchen desk essential for phones! Perfect viewing experience while reducing neck back strain, A must-have for gamers streamers desk, and anyone who values both style and support!
- Sleek & Stable Design fits Otterbox Case: Say goodbye to bent cables, tangles, and tip-overs! LISEN’s stylish adjustable desk phone holder features a built-in charging hole and smart cable management, keeping your phone secure and your workspace clutter-free cool gadgets for men
- ANTI-SLIP DESIGN free hands: The under 10.00 items easy gadgets back and the bottom of this kitchen essentials for women are fully covered by anti-skid silicone, which LISEN stand up desk decor can provide maximum protection device from any scratches and slides
- Your Perfect Viewing Companion:If your product arrives damaged or breaks within 365 days, reach out to LISEN for a quick and hassle-free solution. Struggling with assembly, like tightening the screw? We’ve got your back! Your experience matters to us. (Product including: phone Holder stand*1, screw*1, hexagon screwdriver*1, specification*1)
What to look for
- The Java version printed near the start of the log.
- The Forge version and Minecraft version.
- A mod identifier followed by “has failed to load,” “missing dependency,” or “ticking” errors.
- A stack trace naming a jar that was recently added or updated.
- Memory messages such as out-of-memory or a watchdog timeout.
If the log names a specific mod, restore that mod to the version shipped with RLCraft 2.9.3. An apparently unrelated addition can still conflict during class loading, mixin processing, registration, or world generation.
Bisect added or updated mods
When the log does not identify a clear culprit, use a binary search rather than removing files at random:
- Back up the server and copy the current
modsdirectory. - Disable about half of the mods that were added or updated after the server last worked.
- Start the server and record whether the failure remains.
- If it starts, the conflicting mod is in the disabled half; if it still fails, it is in the enabled half.
- Repeat by halving the suspect group until one mod or combination remains.
- Restore the original pack and remove or downgrade only the confirmed conflict.
This method also catches two individually valid mods that fail only when loaded together. Test after each change and keep the original files outside the live server directory.
4. Check OptiFine on player clients
OptiFine is a client-side graphics mod, so it can crash a player’s game even when the dedicated server is healthy. A 1.12.2 guide associated with RLCraft recommends the latest G5 build rather than E3; community issue reports also describe startup crashes involving OptiFine.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsClient-side recovery
- Remove the OptiFine jar from the client’s mods folder temporarily.
- Launch the unmodified RLCraft 2.9.3 profile and connect.
- If the client now starts and joins, install only the OptiFine build recommended for the pack’s 1.12.2 environment.
- Do not place OptiFine in the dedicated server’s mods folder unless the pack documentation explicitly requires it.
If the crash remains with OptiFine removed, return to the client crash report and check for a different graphics, memory, or mod-loading error.
Rank #4
- Easy Installation: Our gaming lights have been designed to enhance your entertainment experience. Simply position the led light bar next to your TV or game console to create a game room environment with ease. They come with USB power and a 60 inch cord for direct mounting and mobility
- Audio Syncing & Extensive Mode: The built-in high-sensitivity music sensor allows you to sync the TV led lights to your favorite music. Lights react and move to the beat of music, film and game audio, creating an incredible immersive sound and light experience – and all without the need for an additional hub. You can choose from 64+ patterns, including strobe, illusion, jump, energy, gradient, running, chasing, fluttering mode etc. Each mode can be applied to different scenes
- 64+ Chasing IC+RGB & W Effect: The independent control design of IC+RGB and white all-in-one multifunctional rgbw led bar lights monitor backlight allows you to easily switch the led lights for desk between IC+RGB and white to enjoy a variety of lighting effects, you can choose white lighting mode with high brightness for better illumination when working, etc. Choose IC+RGB lighting mode when you need to create an entertaining atmosphere for the light show, 16 million colours of Color changing rgb light bar let you dance to the beat and create a dynamic party atmosphere
- Dynamic and Dimmable Lights: 1%-full brightness free brightness adjustment gives you the flexibility to adjust dimmable led light bar for room decorations or a variety of occasions
- USB Powered: USB light bars for room can be powered by powernank, usb charger, TV, Monitor, laptop PC mainframe, making behind TV led lighting bar easy to install in any location.TV led lights are powered by the TV usb interface / PC mainframe, can be turned on/off synchronously with TV / PC
5. Distinguish world-generation freezes from a true crash
RLCraft creates demanding terrain. Generating a large amount of unexplored land while several players move in different directions can produce a long tick freeze, a watchdog termination, or an out-of-memory error. To a player, that may look identical to a server crash.
Use a controlled test
- Stop new exploration and restart the server with no configuration changes.
- Have one player connect near an already generated area.
- Watch memory use and the console while that player travels a short distance.
- Compare the timing of the failure with chunk-generation messages or a watchdog timeout.
Pre-generate before opening the server
Pre-generating the intended play area lets the server perform chunk generation before players create a burst of simultaneous work. Use a chunk-pregeneration tool compatible with Minecraft 1.12.2 and test it on a copy of the world first. A search result mentioned a 10,000-block radius and a “more than 10 players” threshold, but those figures were not tied to a verified source; treat them as planning examples, not requirements.
Keep a backup before running any pregenerator. Large radii can consume substantial disk space and time, and an interrupted job should not be allowed to overwrite your only world copy.
6. Give the server enough memory without trusting one magic number
Published hosting advice conflicts on RLCraft memory sizing, and none of the figures is an official requirement. One estimate suggests about 6 GB before anyone joins plus roughly 0.2 GB per online player. Another recommends 4 GB for one to three players, 6 GB for five to ten, and 8–10 GB for larger groups. A separate host describes 3–4 GB as a CurseForge minimum, but that figure was not independently confirmed.
| Guidance found in hosting articles | How to interpret it |
|---|---|
| About 6 GB base plus approximately 0.2 GB per player | Use as a starting estimate, not a guarantee |
| 4 GB for 1–3 players | May work for a lightly explored world; monitor memory and pauses |
| 6 GB for 5–10 players | A commonly suggested middle tier |
| 8–10 GB for larger groups | More headroom for concurrent exploration, but still hardware-dependent |
| 3–4 GB minimum | Unconfirmed host claim; do not treat it as an official floor |
A practical starting point is 6 GB for a small server, followed by observation rather than blind allocation. Increase memory only when logs and monitoring show heap exhaustion; allocating more RAM cannot fix a Java-version mismatch, a broken mod, or a network firewall.
Best Value
- Compatible with Wide Screens - To ensure compatibility with the dual monitor mount, your each monitor must meet three conditions at the same time: First, computer screens size range: 13 to 32 inches. Second, screen weight range: 4.4 to 19.8 lbs. Third, the back of the monitor screen must have VESA mounting holes with a pitch of 75x75mm or 100x100mm.
- Regarding the compatibility with desks - Your desk must meet three conditions at the same time: First, desk material: Only wooden desks are recommended, plastic or glass desks cannot be used. Second, desk thickness range: 0.59" - 3.54". Third, the bottom of the desk should not have any cross beams or panels, as this will interfere with installation. We recommend carefully checking that your desk and monitors meets all above conditions before purchasing.
- Dual C-Clamp Hold - Worried your dual monitors might wobble or slip? Our upgraded base uses a larger platform plus a dual C-clamp structure to lock the dual monitor arm firmly to your desk. Each arm safely keeps your screens steady while you type, click and game—no shaking, no sliding, just a clean and secure setup you can trust every day. It also provides Grommet Mounting installation choice, both options ensure stable and secure fixation for your 0.59" - 3.54" desk.
- Full-Motion Adjustment For Comfortable View - Pull the screen closer when you’re deep in a spreadsheet, push it back to watch videos, or rotate to portrait for coding — moving everything smoothly with just one hand. The monitor stand offers +85°/-50° tilt, ±90° swivel and 360° rotation. Raise your monitor up to 15.75″ to support a healthy sitting posture. Whether you’re working from home, gaming through the night, or switching between video calls and documents, getting the screens to your natural line of sight helps relieve neck, shoulder and back strain so you can stay focused longer with less fatigue.
- Keep Your Desk Organized: By lifting both screens off the desktop, this dual monitor stand opens up valuable space for your keyboard, notebook, docking station or a simple, clutter-free work area. Built-in cable management guides wires along the arms, keeping cords out of sight and out of the way. Enjoy a tidy, modern workstation that looks as good as it feels to use.
Separate heap problems from system pressure
- Out-of-memory in the Java log: reduce simultaneous exploration, pre-generate terrain, and review the heap allocation.
- The operating system is swapping: leave memory for the operating system and other services instead of assigning nearly all physical RAM to Java.
- A watchdog timeout with normal memory: investigate a long-running mod task or chunk-generation burst rather than adding RAM automatically.
7. Fix players who cannot join
If the server reaches a ready state but players cannot connect, treat the problem as a version, address, port, or access-control issue.
Recommended Free Tools
- Confirm the player is running RLCraft 2.9.3 on Minecraft 1.12.2 with the same mod set as the server.
- Use the server’s correct public address or local address; do not give remote players a private LAN address.
- Forward or allow TCP port 25565 on the router and host firewall unless you deliberately configured another port.
- Check the server’s whitelist and add the player’s exact in-game name.
- Read the client disconnect message and the server console at the same moment; the paired messages usually identify a handshake mismatch or a network rejection.
Opening a port does not bypass a whitelist, and a correct whitelist does not help if the port is blocked. If local players can connect but remote players cannot, focus on router forwarding, firewall rules, and the public address. If nobody can connect, verify that the server is listening and that the startup log did not report a later crash.
8. Check server properties and the EULA
The file eula.txt must contain an acceptance of Minecraft’s EULA before a standard server will continue running. Set it only after reading the EULA and do not edit it while the server process is active.
Search output also associates enable-command-block=true in server.properties with correct generation of certain structures. That setting was not backed by a verified source, so treat it as a compatibility check for worlds or structures that specifically require command blocks, not as a universal RLCraft fix. Change one property at a time and keep a copy of the original file.
9. Rule out launcher-specific failures
Older issue threads from 2019–2020 describe RLCraft startup failures in third-party launchers, including a MultiMC report for 1.12.2 and a CurseForge issue titled “Crashing on start up.” Those reports may not apply to current launcher versions, but they are useful when the server is fine and only one launcher fails.
Launcher isolation test
- Export or reinstall the exact RLCraft 2.9.3 profile from the distribution source you normally use.
- Launch it once with no extra shaders, performance mods, or custom JVM arguments.
- Compare the generated client log with the failing profile.
- Re-add custom settings one at a time until the failure returns.
Do not delete the server world to fix a launcher-only crash. Client installation problems and server data are separate failure domains.
10. A complete recovery sequence
Use this order when you need a repeatable repair rather than a single guess:
Quick Recap
- Stop the server and back up the entire server directory, especially the world,
mods,config, and property files. - Confirm the launch runtime is Java 8.
- Confirm Minecraft 1.12.2, Forge 14.23.5.2860, and RLCraft 2.9.3.
- Accept the EULA in
eula.txtif this is a new installation. - Start with the original mod set and capture the complete log.
- Remove or isolate only mods that were added or updated after the last successful start.
- Test a client without OptiFine, then add the compatible 1.12.2 build if needed.
- Pre-generate a modest test area on a world copy if the log points to chunk generation or memory pressure.
- Set a measured RAM allocation and monitor heap use, system memory, and tick time.
- For connection failures, verify release matching, TCP 25565, firewall rules, and the whitelist.
- Restore the backup if a change damages the world or makes the log less informative.
Symptoms and the most likely first action
| Symptom | First action | Next branch if it persists |
|---|---|---|
| AppClassLoader cast error | Switch the server to Java 8 | Verify Forge 2860 and inspect the full stack trace |
| Server exits before “Done” | Check Java, Forge, and the exact pack release | Bisect recently changed mods |
| Crash names OptiFine | Remove OptiFine from the client | Install the compatible 1.12.2 G5 build only after a clean test |
| Freeze or out-of-memory while exploring | Stop new exploration and inspect chunk-generation timing | Pre-generate terrain and reassess RAM |
| Client rejected during login | Match every client to RLCraft 2.9.3 | Check Forge, mod lists, whitelist, port, and firewall |
| Only one launcher crashes | Start a clean 2.9.3 profile | Remove custom JVM arguments and extras one at a time |
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
