gradlew setupDecpmpWorkspace eclipse BUILD FAILED

[Crazy__Jacky]

To honour the JVM settings for this build a new JVM will be forked. Please consider using the daemon: https://docs.gradle.org/2.14/userguide/gradle_daemon.html.

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'forge'.
> Could not resolve all dependencies for configuration ':classpath'.
   > Could not resolve net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT.
     Required by:
         :forge:unspecified
      > Could not resolve net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT.
         > Unable to load Maven meta-data from https://files.minecraftforge.net/maven/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml.
            > Could not GET 'https://files.minecraftforge.net/maven/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml'.
               > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED
 

[Laike_Endaril]

Try closing your IDE, opening cmd/terminal, going to the project directory, and running

gradlew setupDecompWorkspace eclipse

Then reopen your IDE and maybe refresh it, see if that helps