I am updating an object of type X and its children Y using LINQ to SQL and then submitting changes and getting this error

Example Code

X objX = _context.X.ToList().Where(x => x.DeletedOn == null).First();
objX.DeletedOn = DateTime.Now;

EntitySet<Y> objYs = objX.Ys;
Y objY = objYs[0];
objY.DeletedOn = DateTime.Now;

_context.SubmitChanges();

On SubmitChanges() I get an exception "1 of 2 Updates failed", no other information as to why that happened. Any ideas?

Also the exception type is ChangeConflictException

c# sql-server linq-to-sql
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