Eclipse internal error "Polling news feeds"

Turning off the news feed does solve this problem (Per @Pyves, unchecking "Enable automatic news polling" from Preferences-> General -> News), but be aware that you may get other issues because of the too-new JDK. Noga Rotman just spent several hours working out for me that Eclipse not being able to find JUnit, even though it was installed and correctly on the classpath, was because of using the new JDK (the one that is causing these same issues).

You can solve the underlying issue by uninstalling your current version of the JDK and installing an old version, then reinstalling Eclipse. If you have the Oracle JDK you can find uninstall instructions here and and Java SE Development Kit 8u191 (which fixed my issues) is here.

This is caused by the http://openjdk.java.net/jeps/320 - which is removal of Java EE and CORBA Modules from the standard Java 11 version.

As mentioned by @Pyves, the simple way would be unchecking "Enable automatic news polling" from the Preferences-> General -> News

But if you still need this, you can install "javax.*" bundles from the eclipse orbit repository. Here is the latest stable repo url: http://download.eclipse.org/tools/orbit/downloads/drops/R20180905201904/repository

This indeed seems to be an issue when Eclipse is run with Java 11. I have created Bug 539545 to report this.

In the meantime, you can work around this issue by disabling news feed polling. To do so, go to Preferences... -> General -> News, and untick the Enable automatic news polling option:

The error window will no longer appear.