I think i made it work but with a very ugly workaround, I manually downloaded org.eclipse.equinox.common-3.14.0.jar file renamed it to org.eclipse.equinox.common-3.15.100.jar and placed it under my directory: C:\Users\<your user name>\.gradle\caches\modules-2\files-2.1\org.eclipse.platform\org.eclipse.equinox.common\3.15.100.
At least it can build now.
But let's come back to the root problem, I know the problem comes from the version of "org.eclipse.equinox.common" library, seems newer version 3.15.100 is compiled with JDK11 instead of JDK8. But i see we already specified to use 3.14.0 version in the build.gradle file. Forgive me i am new to gradle, I don't understand why when i build it is still downloading 3.15.100 version (the latest version). Looks like some other libraries are depending on this latest version, so it got downloaded instead of version 3.14.0.
Is there a easy way to force use 3.14.0 then we can probably find and downgrade those libraries which depends on 3.15.100 version ?
I see, thanks for explaining. I am new to Grandle, will try to do some research and fix.
Confirming the issue.
Unfortunately this is a standard Gradle dependency hell situation. Some package was updated and some transient package (org.eclipse.equinox.common) is in the new version compiled with Java 11, so it does not fit rest of the application and build fails. I guess, already had few issues like this.
The solution is to fiddle with version specifiers and downgrade packages which need to be downgraded. Unfortunately I won't have time to look at it in few weeks.
Feel free to fix this yourself if you want to have it faster. If you submit a working PR to this issue I will provide 3 months of premium membership as a bounty.
Kind regards,
Karel