Everything was fine until an hour or so ago!!! I use CS6 MasterSuite because my client refuses to update. I have been heavily using InDesign CS6 over the last few weeks. Today the computer crashed for some reason, and when I restarted InDesign it now opens with an error screen saying "Cannot load the METADATA UI.APLN plug-in. It is dependent on the METADATA.rpln plug-in, which failed to load. Please check documentation for the METADATA.RPLN plug-in." I have goggled and searched the forums but can find no reference to anyone else having this issue. The other Master Suite programs seem to work fine. How do I correct it? Urgent help needed!
From the name of the plugins I'm presuming you run some version of Windows.
First thing I would try is trashing the prefs (which probably will not help, but it's fast and it might). See Replace Your Preferences
Next thing would be Windows System Restore and go back a day.