Could not run phased build action using connection to Gradle

I’m having various Gradle problems after a new clean install.
They seem to be associated w/ this “Problem” message:

Could not run phased build action using connection to Gradle distribution ‘https://services.gradle.org/distributions/gradle-6.8-bin.zip’.
Initialization script ‘Z:\eclipse-workspace.metadata.plugins\org.eclipse.buildship.core\init.d\eclipsePlugin.gradle’
Could not compile initialization script ‘Z:\eclipse-workspace.metadata.plugins\org.eclipse.buildship.core\init.d\eclipsePlugin.gradle’.
startup failed:
General error during semantic analysis: Unsupported class file major version 60
java.lang.IllegalArgumentException: Unsupported class file major version 60
at groovyjarjarasm.asm.ClassReader.(ClassReader.java:196)

at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at java.base/java.lang.Thread.run(Thread.java:831)
1 error

I’ve already tried deleting .gradle & “Gradle->Refresh Gradle Project”.

My Java install is clean:

C:>java -version
java version “16.0.1” 2021-04-20

& confirmed Eclipse is pointing to it (“Preferences->Java->Installed JREs”).

My Installation details:

Buildship: Eclipse Plug-ins for Gradle 3.1.5.v20210113-0929
Eclipse IDE for Java Developers 4.20.0.20210612-1200
Windows 10.

Eclipse Install Err Log:

!ENTRY org.eclipse.buildship.core 2 2 2021-07-09 11:22:05.951
!MESSAGE Initialize project testgradleprj failed due to an error in the referenced Gradle build.
!STACK 0
org.gradle.tooling.BuildException: Could not execute build using connection to Gradle distribution ‘https://services.gradle.org/distributions/gradle-6.8-bin.zip’.