The most common cause of the JNI error while trying to set up a Minecraft server is due to the Java version installed on the machine being outdated.

<tl;dr> To fix the Eclipse “No Java virtual machine was found” error, simply edit the eclipse-inst.ini file and add the -vm flag, which points it to the java utility in the JDK bin directory: ...

The default-java folder is a symbolic link to the actual location of the JDK install on Ubuntu. When you reference the JDK install location in applications or in environment variables such as ...