Go to Project Properties > Compiler and change Source Compatibility to 1.8 . Error 3: "Unsupported major.minor version 52.0" at runtime Cause: Your application was compiled with Java 8 (version 52) but deployed to a Java 7 runtime.
SetJavaHome C:\path\to\jdk1.8.0_421 Or launch from command line: jdeveloper 12.2.1.4 java version
Introduction Oracle JDeveloper 12c (12.2.1.4.0) is a stable, widely-used integrated development environment for building Oracle Fusion Middleware applications, ADF (Application Development Framework), and general Java EE applications. A common point of confusion for developers is the correct Java version required to install, run, and compile projects with this specific IDE release. Go to Project Properties > Compiler and change