Decision::
Open the .project file inside the project folder
1) <buildSpec> <name>org.eclipse.jdt.core.javabuilder</name>
<buildSpec>
...
...
...
<buildCommand>
<name>org.eclipse.jdt.core.javabuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
2) <natures> <nature>org.eclipse.jdt.core.javanature</nature>
<natures>
...
<nature>org.eclipse.jdt.core.javanature</nature>
</natures>
3) "" → " Java" → "" → replicaisland/gen