Ошибка сервера Minecraft

Я точно следовал руководству на этом сайте, чтобы установить сервер Minecraft в моей системе Ubuntu Server 20.04, и я получаю следующий вывод, используя показанные команды:

owner@mk-dell-t110:~$ sudo systemctl start minecraft@survival
owner@mk-dell-t110:~$ sudo systemctl status minecraft@survival
● minecraft@survival.service - Minecraft Server: survival
     Loaded: loaded (/etc/systemd/system/minecraft@.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Sun 2021-09-26 04:46:11 UTC; 23s ago
    Process: 583600 ExecStart=/usr/bin/screen -DmS mc-survival /usr/bin/java -Xmx4G -jar minecraft_server.jar nogui (code=exited, status=0/SUCCE>
    Process: 583619 ExecStop=/usr/bin/screen -p 0 -S mc-survival -X eval stuff "say SERVER SHUTTING DOWN IN 5 SECONDS. SAVING ALL MAPS..."^M (co>
   Main PID: 583600 (code=exited, status=0/SUCCESS)

Sep 26 04:46:11 mk-dell-t110 systemd[1]: minecraft@survival.service: Scheduled restart job, restart counter is at 5.
Sep 26 04:46:11 mk-dell-t110 systemd[1]: Stopped Minecraft Server: survival.
Sep 26 04:46:11 mk-dell-t110 systemd[1]: minecraft@survival.service: Start request repeated too quickly.
Sep 26 04:46:11 mk-dell-t110 systemd[1]: minecraft@survival.service: Failed with result 'exit-code'.
Sep 26 04:46:11 mk-dell-t110 systemd[1]: Failed to start Minecraft Server: survival.
owner@mk-dell-t110:~$ journalctl -u minecraft@survival.service
-- Logs begin at Thu 2021-09-23 21:52:02 UTC, end at Sun 2021-09-26 04:46:37 UTC. --
Sep 26 00:25:48 mk-dell-t110 systemd[1]: Started Minecraft Server: survival.
Sep 26 00:25:48 mk-dell-t110 screen[558000]: No screen session found.
Sep 26 00:25:48 mk-dell-t110 systemd[1]: minecraft@survival.service: Control process exited, code=exited, status=1/FAILURE
Sep 26 00:25:48 mk-dell-t110 systemd[1]: minecraft@survival.service: Failed with result 'exit-code'.
Sep 26 00:25:48 mk-dell-t110 systemd[1]: minecraft@survival.service: Scheduled restart job, restart counter is at 1.
Sep 26 00:25:48 mk-dell-t110 systemd[1]: Stopped Minecraft Server: survival.
Sep 26 00:25:48 mk-dell-t110 systemd[1]: Started Minecraft Server: survival.
Sep 26 00:25:48 mk-dell-t110 screen[558027]: No screen session found.
Sep 26 00:25:48 mk-dell-t110 systemd[1]: minecraft@survival.service: Control process exited, code=exited, status=1/FAILURE
Sep 26 00:25:48 mk-dell-t110 systemd[1]: minecraft@survival.service: Failed with result 'exit-code'.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Scheduled restart job, restart counter is at 2.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: Stopped Minecraft Server: survival.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: Started Minecraft Server: survival.
Sep 26 00:25:49 mk-dell-t110 screen[558049]: No screen session found.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Control process exited, code=exited, status=1/FAILURE
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Failed with result 'exit-code'.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Scheduled restart job, restart counter is at 3.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: Stopped Minecraft Server: survival.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: Started Minecraft Server: survival.
Sep 26 00:25:49 mk-dell-t110 screen[558072]: No screen session found.
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Control process exited, code=exited, status=1/FAILURE
Sep 26 00:25:49 mk-dell-t110 systemd[1]: minecraft@survival.service: Failed with result 'exit-code'.
owner@mk-dell-t110:~$ 

Я новичок в Ubuntu Server, поэтому прошу прощения, если это не очень помогает при диагностике ошибок. Как я уже сказал, я следовал связанному руководству точно до части с надписью «Предоставление нового экземпляра сервера Minecraft на том же хосте». На данный момент мне нужен только один сервер Minecraft.

Обновление: я только что попытался запустить сервер вручную с помощью команды java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui, и вот результат:

owner@mk-dell-t110:/opt/minecraft/survival$ ls
eula.txt  minecraft_server.jar
owner@mk-dell-t110:/opt/minecraft/survival$ java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui
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 55.0
owner@mk-dell-t110:/opt/minecraft/survival$ 

Это сразу после того, как я попытался проверьте, установлена ​​ли у меня Java, с помощью команды sudo apt install wget screen default-jdk nmap из учебника на веб-сайте (ранее ссылка выше), которую я выполнил, чтобы зайти так далеко.