When I click on Check for Update the Lightroom Plugin Manager, it says that I have ExifMeta 3.8.4 and that 3.8.5 is available for download.  After I download 3.8.5 onto my MacBook Pro running OS 10.6.8, I click Update Plugin and navigate to the newly created directory RC_ExifMeta_LrPlugin_3.8.5, containing the license, readme, and ExifMeta.lrplugin files.  The ExifMeta.lrplugin file is grayed out, so I can't highlight it and choose it.  What should I do?