I am having the same issue trying to load data under the WaterDistribution Feature Dataset in the Local Government Model. Does anyone know how to fix this problem? I was able to load data in other feature classes, but it seems like some are greyed out (ex. wSystemValve, wMain, etc.) I am not sure what you mean by deleting and reinstating from a backup, but if that worked for you can you please explain to me how you did that?
Thank you!