How to Organize and Name Minecraft Server JAR Files

Direct answer

The JAR filename in your startup command must exactly match the file on disk. Renaming the JAR can be useful for upgrades, but does not itself update Minecraft or Java.

Recommended procedure

Stop the server and record the current working startup command.
Find the downloaded server JAR name; on Linux, filenames are case-sensitive.
Either rename the downloaded file to match the startup command or change -jar to match the new filename.
For a script such as java -Xmx4G -jar server.jar nogui, verify that server.jar is present in the script’s working directory.
Start from the server directory and look for a Java JAR error before modifying any world files.

Why this matters

A control panel may manage the startup JAR in a separate setting. Changing a filename in an upload area while the panel still points to the old file produces Unable to access jarfile or another launcher error.

Practical example: Example: a Linux startup script referring to paper.jar fails when the uploaded file is Paper.jar; Linux filenames are case-sensitive. If the panel keeps changing the startup command, fix its managed JAR setting rather than repeatedly renaming the file. When using a versioned filename, make the new name explicit in the launch script.

How to verify the result

Use ls -l on Linux or dir on Windows to verify the exact file.
Run the saved start command and confirm the expected server software/version appears in startup logs.
Keep the previous JAR for rollback, but restore the corresponding backup if the world was upgraded.

Version and compatibility notes

Do not rename a client mod or installer JAR and expect it to function as a dedicated server JAR.
Quote paths that contain spaces in launch scripts.

Official references

These sources were checked for the current MSH revision. Version-sensitive details should always be confirmed against the project documentation for the release you run.

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