title: Eclipse - Unexpected error loading extension: org.eclipse.equinox.p2.metadata.repository.compositeRepository
body: <p>Suddenly I was not able to check for Eclipse updates and every connection to an online repository was failing do to the following error, visibile in <code>ECLIPSE_WORKSPACE/.metadata/.log</code></p>
  
  <pre><code>    !ENTRY org.eclipse.equinox.p2.metadata.repository 4 0 2020-05-15 09:58:58.981
      !MESSAGE Unexpected error loading extension: org.eclipse.equinox.p2.metadata.repository.compositeRepository
      !STACK 0
      java.lang.LinkageError: loader constraint violation: loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @59ec6f70 wants to load interface org.apache.http.client.CredentialsProvider. A different interface with the same name was previously loaded by org.eclipse.osgi.internal.loader.EquinoxClassLoader @58c5820f. (org.apache.http.client.CredentialsProvider is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @58c5820f, parent loader 'platform')
  </code></pre>