Failed opening required plugin context_reaction_region.inc

Just upgraded and saw the following when attempting to add a context:

Fatal error: require_once() [function.require]: Failed opening required '/pathToD7/sites/all/modules/context/plugins/context_reaction_region.inc' (include_path='.:/usr/share/php:/usr/share/pear') in /pathToD7/includes/bootstrap.inc on line 2789

Just tried again and I don't see the error?

Perhaps a clear cache was needed?

I don't have the file context_reaction_region.inc in the plugins subdirectory.