The Energy+.idd is the input data definition file that tells the program how many and what type of fields to expect for each object. You should have one located in the directory C:/EnergyPlusV-X-X-X
If it somehow was deleted then you should re-install. Otherwise, not sure why your install isn't seeing the file. Would probably suggest a re-install in that scenario as well.
Good luck,
Jason
--Edwin LeeDoctoral Candidate, Oklahoma State UniversityASHRAE Student Member, Former ASHRAE OSU Student Branch PresidentOffice: ATRC 303: 405-744-3727
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