Common Reasons a Minecraft Server Won't Start

5 min. readlast update: 09.25.2024

This guide will cover a few reasons and tips regarding common issues surrounding server crashes and failures to start. 

👋 SimpleGameHosting provides premium support to all customers for no additional charge. If your server is crashing or failing to sure, reach out to the support team! They are there to help and fix issues exactly like this! 

Mod Related Crashes

Mods are a great tool for enhancing Minecraft's gameplay, but they can come at the cost of introducing a variety of failure points inside of a server. For this section, we'll be going over a few of the most common problems stemming from mod installations.

Missing Dependencies

Many mods across the community have 'dependencies', which are mods that must be installed alongside the mod that you intend to install to your client and/or server. Typically, mod creators will list any dependencies that a mod requires within the description of their mod, which makes it much easier to determine what additional mods you'll need to install for your server to work correctly!

Typically when a dependency is missing, the server will produce an error within the console naming specifically what is missing, or the server will produce a crash report in the crash-reports folder with the same information. Regardless of which area the missing dependency is reported, be sure to download the indicated version and add it to your server!

Wrong Mod Versions

Another common problem when it comes to modding is installing the wrong version of a mod. Mod versions must match the version of the server, as well as the mod loader that is being used (I.E a server running Forge for 1.20.2 must have mods that are for Forge 1.20.2, otherwise, they will not work!)

Much like the previous error, the server will either print the error out in the console, or it will generate a crash report detailing which mod is the wrong version. Likewise, simply replacing the offending mod with the correct version should resolve the issue!

RAM Error

RAM errors occur when a server tries to use more RAM than what it has access to. Typically, this is indicated by a random crash while the server is up, or crashing during random points during startup. Additionally, crashes due to RAM do NOT produce a crash report. As such, if your server crashes while running and it did not produce a crash report, the problem is likely related to your server's RAM!

Generally, there are two ways to attempt to remedy RAM related crashing: Pregenning the world, or upgrading the server to a bigger package. It is worth noting though that server's crashing due to RAM during start-up can only be fixed by upgrading. 

Server Watchdog

One of the more perplexing crashes is one known as a 'watchdog'. A watchdog error typically indicates that the server has frozen, and has shut itself down as a result of this. The typical indication for a server watchdog is a crash report titled 'watching server'.

One of the biggest reasons this happens is because of an error with specific entities or with broken world generation. As such, the typical solution to a server watchdog is typically to revert to the last available backup, if it is available.

Removing Mods or Changing Versions

When removing mods or changing versions, your server will occasionally no longer be able to stop. This could be due to the mods being outdated or for the wrong version as mentioned above. 

It could also be due to the world needing to be reset. Removing mods or changing Minecraft versions with mods often requires a world reset. 

Here is a complete guide on resetting the world on a Minecraft server that will help you get a new world in these cases. 

Vanilla Servers

Vanilla servers are much less likely to have issues starting then modded servers, but some are still worth mentioning. These can occur on modded servers as well as plugin based servers. 

Entity or World Corruption

Sadly, one of the most common reasons for a vanilla server to not start is the world being corrupt. This could be due to a glitch in Minecraft or due to changing your server's version. 

The best way to solve this problem is to reset your world on the server. Sadly, this does result in you losing all progress on the server. 

Running Out of RAM

Vanilla Minecraft servers have consistently required more RAM as Minecraft has grown and had new features added. 

If your server is crashing on start-up, it could be due to the server running out of RAM. This is especially possible if the server is a larger server with a lot of things occurring in the server's spawn or loaded chunks. 

Here is a guide on upgrading your server to add more RAM

Missing server.jar File

Another common reason a Minecraft server won't start is due to the server.jar file missing. This may occur when deleting the files to reset your server. 

To get a new server.jar file on a SimpleGameHosting server, just navigate to the "Versions" tab and select the server software you want to install. Find the version of Minecraft you want to install that software for and click "Install" under it. 

Confirm you want to install the software, and you are done! The server files will now exist and you can start the server on the "Console" tab. 

Plugin Servers

Plugin-based servers are typically very solid when starting and generally will just have vanilla-related issues when it comes to not starting. 

Plugin Errors

The only reason a server might not start running plugins, outside of vanilla related issues, is plugin incompatibility. Generally in these cases, it is because a plugin is for a version of Minecraft that is different from the server. For example, a 1.19 plugin will not work in 1.21, and in some cases, can stop the server from starting. 

Plugin server are very robust though and will usually start just with the plugin inactive. 

🗒 If you are a SimpleGameHosting customer, there is no need to worry about your server not starting. The support team is there to help! Just reach out via live chat, and they will diagnose the issue for you!

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