2482358 - DTR server is unavailable error occurs in NWDS due to VfsException

The following error message occurs in NWDS when you try to login to NWDI or during check out:

!MESSAGE The server 'http://<host>:<port>/dtr/' is unavailable
[EXCEPTION]
[VFS version: @@client.version@@] com.tssap.dtr.client.lib.vfs.VfsException: The server 'http://<host>:<port>/dtr/' is unavailable
   at com.tssap.dtr.client.lib.vfs.impl.VersionedFileSystemManager.pingCheck(VersionedFileSystemManager.java:441)
   at com.tssap.dtr.client.lib.vfs.impl.VersionedFileSystemManager.getVersionedFileSystemManager(VersionedFileSystemManager.java:212)
   at com.tssap.dtr.client.lib.vfs.VersionedFileSystemFactory.getVersionedFileSystemManager(VersionedFileSystemFactory.java:46)
   at com.tssap.dtr.client.eclipse.vfs.VfsManagerProvider.getVersionedFileSystemManager(VfsManagerProvider.java:333)
   at com.tssap.dtr.client.eclipse.ui.treeBrowser.RepositoryView$41.doDtrJobInWorkerThread(RepositoryView.java:1690)
   at com.tssap.dtr.client.eclipse.job.DtrJob$3.run(DtrJob.java:164)
   at com.sap.ide.dii05.util.internal.lock.DiiConsistencyServiceImpl.executeInDevConfLock(DiiConsistencyServiceImpl.java:108)
   at com.tssap.dtr.client.eclipse.job.DtrJob.runInSync(DtrJob.java:160)
   at com.tssap.dtr.client.eclipse.job.DtrJob.syncExec(DtrJob.java:127)
   at com.tssap.dtr.client.eclipse.ui.treeBrowser.RepositoryView.getVfsManager(RepositoryView.java:1684)

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KBA , BC-DWB-JAV-DII , Development Infrastructure Integration , Problem