LINQ Join Throws An Error Saying "There is already an open DataReader associated with this Command w

I have a Linq join and have populated viewmodel using that join. On running, there is an error on that join saying

There is already an open DataReader associated with this Command which must be closed first

Below is my join

public List<GallerySisterComanyVM> GetAllGallery()
{
    var list = (from GI in uow.Repository<GalleryImage>().GetAll()
        join SC in uow.Repository<SisterCompany>().GetAll() on GI.SisterCompanyId equals SC.SisterCompanyId
        select new GallerySisterComanyVM
        {
            GalleryImageId=GI.GalleryImageId,
            Status=GI.Status,
            Image=GI.Image,
            SisterCompanyName=SC.SisterCompanyName
    }).OrderByDescending(x=>x.GalleryImageId).ToList();

    return list;
}