Diagnosing Minecraft server errors

Day to day, we are constantly blamed for server crashes or servers not working, however, 95% of the time, the issue was caused by the server owner/plugins or mods that are installed. In this guide, I will explain common errors so that you can distinguish between errors that are caused by what you have done and whether it's our fault.

Server errors can be found in the server.log or latest.log file, which you can find either using the file manager or FTP. Please note that if you log file is over 100Mb, you will need to delete it, restart your server and then edit it, to view the file using the file manager.

[WARNING] **** FAILED TO BIND TO PORT!

This is a very comon error and is simple to fix. This error means that the IP and server port is not set in the server.properties file to what it should be. What you need to do is to reset your server.properties. Do this by going to file manager -> right click on the server.properties -> edit -> and click the reset to default button. Followed by a server restart.

[SEVERE]

I can guarantee that you will have SEVERE errors in your server.log / latest.log at some point while hosting a server.

These errors usually appear when a plugin is either outdated, and cannot run with the current server version, corrupt or is missing another plugin / library that it needs in order to run.
An example of this would be Factions requiring a plugin called mcore to run.

Another reason these messages may appear could be because of a problem with a world, or dimension within a world.

How do I fix SEVERE errors?

You'll likely need to do one, or more of the following:

• Try updating the plugin which is mentioned in the SEVERE error
• Attempt deleting and then re-uploading the plugin
• Remove the plugin if no newer version is available, and is not missing any dependencies
• If the SEVERE messages shown relate to loading of a world, please contact support on the link below (submit a ticket) and we can try running the world through the Minecraft region repair tool. Should this not work, or you're ok with starting over we would recommend starting a new world. You can find out how to do this here.

[WARNING] **** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!

This message means that your online-mode in the server.properties is set to false. Having this set to false will allow players with hacked clients onto your server, so it is suggested you change it to true, unless this is intentional of course.

at net.minecraft.server.EntityTNTPrimed.d(EntityTNTPrimed.java:70)

This usually means that someone has been a little silly on your server with TNT. The only way to fix this error is usually to reset the world. You can do this by changing the level name in the server.properties to something else, saving and restarting the server.

java.io.IOException: No space left on device

This error is caused by someone on your server using too much disk space, sometimes log files can become over 100Gb in size if people allow them to. To fix this, you will need to contact support by clicking submit a ticket below.

[SEVERE] java.lang.OutOfMemoryError

This means that you've reached the maximum amount of memory for your tier

You'll need to do one of the following:-

• First, if you don't often restart your server. Restart the server daily
• Update all plugins, some may have memory leaks
• Change modpack to something more "light" such as Tekkit classic, Tekkit Lite, Bytesize pack etc
• Remove some mods / plugins from the server
• If you run multiple world (other than the nether / end dimensions) try removing some that are not so essential.
• Finally, you can always upgrade your server. You can do this easily by clicking the drop down to the right of the restart button and selecting upgrade server.