In Eclipse Oracle Weblogic Server does not appear in the New Server window

I'm trying to add a new server in Eclipse and the Oracle Weblogic Server does not appear in the server type list. I've installed the Oracle WebLogic Server Tools from the Eclipse Marketplace.

The New Server window looks like this:

Eclipse: Version: 2020-06 (4.16.0) Build id: 20200615-1200

Plugin: 17.3.0.201903121357

And here's the Workspace log:

org.osgi.framework.BundleException: Exception in org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.start() of bundle org.eclipse.equinox.p2.reconciler.dropins.
    at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:864)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:792)
    at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:1015)
    at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:365)
    at org.eclipse.osgi.container.Module.doStart(Module.java:605)
    at org.eclipse.osgi.container.Module.start(Module.java:468)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel$2.run(ModuleContainer.java:1845)
    at org.eclipse.osgi.internal.framework.EquinoxContainerAdaptor$1$1.execute(EquinoxContainerAdaptor.java:136)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1838)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1781)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1743)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.dispatchEvent(ModuleContainer.java:1665)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.dispatchEvent(ModuleContainer.java:1)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:234)
    at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:345)
Caused by: java.lang.IllegalStateException: Registry Directory not available: c:\Program Files\eclipse\jee-latest-released\eclipse\p2\org.eclipse.equinox.p2.engine\profileRegistry.
    at org.eclipse.oomph.p2.internal.core.LazyProfileRegistry.getProfileMap(LazyProfileRegistry.java:236)
    at org.eclipse.oomph.p2.internal.core.LazyProfileRegistry.getProfileMap(LazyProfileRegistry.java:227)
    at org.eclipse.oomph.p2.internal.core.LazyProfileRegistry.containsProfile(LazyProfileRegistry.java:208)
    at org.eclipse.equinox.internal.p2.engine.ProfilePreferences.containsProfile(ProfilePreferences.java:115)
    at org.eclipse.equinox.internal.p2.engine.ProfilePreferences.load(ProfilePreferences.java:260)
    at org.eclipse.core.internal.preferences.EclipsePreferences.create(EclipsePreferences.java:370)
    at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:624)
    at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:767)
    at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:630)
    at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:767)
    at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:630)
    at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:767)
    at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:630)
    at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:767)
    at org.eclipse.core.internal.preferences.RootPreferences.getNode(RootPreferences.java:108)
    at org.eclipse.core.internal.preferences.RootPreferences.node(RootPreferences.java:87)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.getSharedPreferences(AbstractRepositoryManager.java:518)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.restoreRepositories(AbstractRepositoryManager.java:1022)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.basicGetRepository(AbstractRepositoryManager.java:182)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:657)
    at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:110)
    at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:105)
    at org.eclipse.equinox.internal.provisional.p2.directorywatcher.RepositoryListener.initializeMetadataRepository(RepositoryListener.java:108)
    at org.eclipse.equinox.internal.provisional.p2.directorywatcher.RepositoryListener.<init>(RepositoryListener.java:63)
    at org.eclipse.equinox.internal.p2.reconciler.dropins.DropinsRepositoryListener.<init>(DropinsRepositoryListener.java:85)
    at org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.watchDropins(Activator.java:515)
    at org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.start(Activator.java:175)
    at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:843)
    at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:1)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:835)
    ... 14 more
java.lang.InterruptedException
    at java.lang.Object.wait(Native Method)
    at org.eclipse.core.internal.jobs.Semaphore.acquire(Semaphore.java:44)
    at org.eclipse.core.internal.jobs.JobManager.join(JobManager.java:914)
    at org.eclipse.core.internal.jobs.InternalJob.join(InternalJob.java:344)
    at org.eclipse.core.runtime.jobs.Job.join(Job.java:547)
    at org.eclipse.equinox.internal.p2.transport.ecf.FileInfoReader.waitOnSelf(FileInfoReader.java:74)
    at org.eclipse.equinox.internal.p2.transport.ecf.FileInfoReader.getRemoteFiles(FileInfoReader.java:110)
    at org.eclipse.equinox.internal.p2.transport.ecf.FileInfoReader.getRemoteFile(FileInfoReader.java:125)
    at org.eclipse.equinox.internal.p2.transport.ecf.FileInfoReader.getLastModified(FileInfoReader.java:130)
    at org.eclipse.equinox.internal.p2.transport.ecf.RepositoryTransport.getLastModified(RepositoryTransport.java:249)
    at org.eclipse.oomph.p2.internal.core.CachingTransport.delegateGetLastModified(CachingTransport.java:397)
    at org.eclipse.oomph.p2.internal.core.CachingTransport.getLastModified(CachingTransport.java:346)
    at org.eclipse.equinox.internal.p2.repository.CacheManager.createCache(CacheManager.java:192)
    at org.eclipse.equinox.internal.p2.artifact.repository.simple.SimpleArtifactRepositoryFactory.getLocalFile(SimpleArtifactRepositoryFactory.java:68)
    at org.eclipse.equinox.internal.p2.artifact.repository.simple.SimpleArtifactRepositoryFactory.load(SimpleArtifactRepositoryFactory.java:92)
    at org.eclipse.equinox.internal.p2.artifact.repository.simple.SimpleArtifactRepositoryFactory.load(SimpleArtifactRepositoryFactory.java:80)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.factoryLoad(ArtifactRepositoryManager.java:92)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:775)
    at sun.reflect.GeneratedMethodAccessor48.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.oomph.util.ReflectUtil.invokeMethod(ReflectUtil.java:119)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager.loadRepository(CachingRepositoryManager.java:423)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager.loadRepository(CachingRepositoryManager.java:214)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager$Artifact.loadRepository(CachingRepositoryManager.java:562)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.loadRepository(ArtifactRepositoryManager.java:131)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.loadRepository(ArtifactRepositoryManager.java:125)
    at org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository.load(CompositeArtifactRepository.java:496)
    at org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository.addChild(CompositeArtifactRepository.java:177)
    at org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository.<init>(CompositeArtifactRepository.java:99)
    at org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepositoryFactory.load(CompositeArtifactRepositoryFactory.java:120)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.factoryLoad(ArtifactRepositoryManager.java:92)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:775)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.oomph.util.ReflectUtil.invokeMethod(ReflectUtil.java:119)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager.loadRepository(CachingRepositoryManager.java:423)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager.loadRepository(CachingRepositoryManager.java:214)
    at org.eclipse.oomph.p2.internal.core.CachingRepositoryManager$Artifact.loadRepository(CachingRepositoryManager.java:562)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.loadRepository(ArtifactRepositoryManager.java:131)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.loadRepository(ArtifactRepositoryManager.java:125)
    at org.eclipse.epp.internal.mpc.ui.catalog.MarketplaceCatalog.lambda$12(MarketplaceCatalog.java:338)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Solution

According to the log file, your Eclipse installation was broken:

Registry Directory not available: c:\Program Files\eclipse\jee-latest-released\eclipse\p2\org.eclipse.equinox.p2.engine\profileRegistry.

The missing p2 profile prevented the installation and uninstallation of plugins (the profile is needed to compute whether something can be installed and if so, which so-called installation units of which version have to be installed).

Make sure that the Eclipse installation directory is writable (in Windows everything in c:\Program Files\ is not writable for a normal user by default) and do not delete the p2 directory.

When the installation is that broken, the only solution is to install Eclipse again. It might be that importing of existing plugins from the old installation via File > Import: Install > From existing Installation will not work either in this case.