Only one of the following can be installed at once: Core Resource Management

Eclipse

When trying to install the IAML project, I was getting the following error from the Eclipse update wizard:

Cannot complete the install because of a conflicting dependency.
  Only one of the following can be installed at once:
    Core Resource Management 3.5.0.v20090512
    Core Resource Management 3.5.2.R35x_v20091203-1235
    Core Resource Management 3.5.1.R35x_v20090826-0451
  Cannot satisfy dependency:
    From: Eclipse Platform 3.5.0.v20090611a
    To: org.eclipse.core.resources
  Cannot satisfy dependency:
    From: Eclipse Platform SDK 3.5.0.v20090423
    To: org.eclipse.platform.feature.group
  Cannot satisfy dependency:
    From: Eclipse SDK 3.5.0.I20090611
    To: org.eclipse.sdk.feature.group
  Cannot satisfy dependency:
    From: IAML Modelling Platform 0.6.0.201109262029
    To: org.eclipse.core.resources

I think the problem is that I was trying to install a plugin that requires 3.5.2 onto an Eclipse that is only at version 3.5.0. If you first update your Eclipse to 3.5.2 (Help > Check for Updates), you will be able to install the plugin without problems.