title: OSGiVersion incompatible with java.lang.String
body: <p>I have imported an already existing Plugin project and now I want to Export it and install it in host.
  So i use File - Export - Deployable plug-ins and fragments - Install into host.</p>
  
  <p>Last week all went fine and I could do the export.
  These last days, i keep getting this error:</p>
  
  <p>An internal error occurred during: "Install Job".
  org.eclipse.equinox.internal.p2.metadata.OSGiVersion incompatible with java.lang.String</p>
  
  <p>Any help/suggestion would be appreciated.</p>
  
  <p>Exception stack trace:</p>
  
  <p>Exception stack trace:  java.lang.ClassCastException: org.eclipse.equinox.internal.p2.metadata.OSGiVersion incompatible with java.lang.String
      at org.eclipse.equinox.internal.p2.metadata.RequiredCapability.getNamespace(RequiredCapability.java:154)
      at org.eclipse.equinox.internal.p2.metadata.RequirementChange.matches(RequirementChange.java:35)
      at org.eclipse.equinox.internal.p2.director.Projector.mergeRequirements(Projector.java:934)
      at org.eclipse.equinox.internal.p2.director.Projector.expandRequirementsWithPatches(Projector.java:593)
      at org.eclipse.equinox.internal.p2.director.Projector.processIU(Projector.java:558)
      at org.eclipse.equinox.internal.p2.director.Projector.encode(Projector.java:223)
      at org.eclipse.equinox.internal.p2.director.SimplePlanner.getSolutionFor(SimplePlanner.java:336)
      at org.eclipse.equinox.internal.p2.director.SimplePlanner.getProvisioningPlan(SimplePlanner.java:381)
      at org.eclipse.equinox.internal.p2.operations.PlannerResolutionJob.runModal(PlannerResolutionJob.java:76)
      at org.eclipse.equinox.p2.operations.ProfileChangeOperation.resolveModal(ProfileChangeOperation.java:115)
      at org.eclipse.pde.internal.ui.build.RuntimeInstallJob.run(RuntimeInstallJob.java:152)
      at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)</p>