Can't start server after java update

Web-UI
1

Hey, I’ve been having an isue with mineos where I can’t start the server after a java update. I followed this tutorial: Upgrading to Java 15 from the MineOS Turnkey ISO . When I press start in the web-ui I get the message: Start server failed 1. These are the mineos logs:

{“level”:“info”,“message”:"[Rammeke] 192.168.1.223 issued command : “start”",“timestamp”:“2021-06-27T20:07:33.432Z”}
{“level”:“info”,“message”:"[Rammeke] received request “start”",“timestamp”:“2021-06-27T20:07:33.433Z”}
{“command”:“start”,“uuid”:“4f325b80-d783-11eb-8944-e7b12fa431f6”,“time_initiated”:1624824453432,“success”:false,“err”:1,“time_resolved”:1624824454597,“level”:“error”,“message”:"[Rammeke] command “start” errored out:",“timestamp”:“2021-06-27T20:07:34.598Z”}

Can someone help, I can’t figure this one out on my own, thanks.

2

Had you tried to update to Java 16? I believe there’s steps further down the post.

3

I updated the server to java 15. Before the update I couldn’t start 1.17 servers, but the rest was fine. Now I can’t start any server.

4

@rammeke_mafkees

Try starting the server manually, from the command line. This will give you direct exposure to the errors or issues within. To do this:

log in to a terminal session as your non-root user, often mc.

In this example testing is the servername, change as necessary.

mc@mineos-tkldev ~$ cd /var/games/minecraft/servers/testing
mc@mineos-tkldev .../servers/testing$ which java
/usr/bin/java
mc@mineos-tkldev .../servers/testing$ /usr/bin/java -jar minecraft_server.1.7.9.jar

The error you get here should explain why no servers start, whether it’s a java issue, jar issue, permissions issue… etc. If you share the output, we can help you interpret it.

5

I get the following result:

Error: Unable to access jarfile minecraft_server.1.7.9.jar

6

Be sure to update the server jar, as well, to match the jar in your directory.

ls to list the files.

7

I get this error message:
Error: LinkageError occurred while loading main class net.minecraft.server.Main
java.lang.UnsupportedClassVersionError: net/minecraft/server/Main has been compiled by a more recent version of the Java Runtime (class file version 60.0), this version of the Java Runtime only recognizes class file versions up to 59.0

8

Java 15 only recognizes up to 59, so you will need Java 16.

9

Uhh, how do I go about doing that?

10

The same way you got 15 going. I updated the previous page for 16, too.

11

I updated java. After that I wasn’t able to start the server from the mineos webui, but I was able to start the server manually.

12

Most likely issue now is that the server has been inadvertently started as root.