DataClassesDatacontext Stackoverflow when submitting changes

I am currently trying to update values in my Database. My code worked flawlessly until I've added a new value to the Database. I have updated my DataClasses1.dbml and it shows the new column I have added to the Database. Still I am getting a Stackoverflowexception when context.SubmitChanges() gets called. The ChangeSet contains 2 Objects which should be updated (update 5 columns per row in this case)

            var customers = new List<Customer>();
            using (var context = new DataClasses1DataContext())
            {
                var result = from custs in context.Customer
                             where custs.ACTION_ID == desRequest.First().ACTION_ID &&
                                    !custs.ARCHIVATED
                             select custs;

                Inputvalidation.SetAddressLines(ref result);
                context.SubmitChanges();
                customers = result.ToList();
            }

context.GetChangeSet shows:

{{Inserts: 0, Deletes: 0, Updates: 2}}
    Deletes: Count = 0
    Inserts: Count = 0
    Updates: Count = 2

Before the update of each row I'm adding new customers from a json-post in nancyfx with this code (which to my surprise still works as intended)

    private static bool AddItems(string request)
    {
        // Hier alle sammeln und in einem wisch rein
        var customers = JsonConvert.DeserializeObject<IEnumerable<Customer>>(request);
        foreach (var cstmr in customers)
        {
            using (var context = new DataClasses1DataContext())
            {
                context.Customer.InsertOnSubmit(cstmr);
                try
                {
                    context.SubmitChanges();
                }
                catch (Exception)
                {
                    //TODO: Hier ggfs. reparieren
                    context.SubmitChanges();
                    return false;
                }
            }
        }
        return true;
    }

These are the error-details: "Das Programm "[8028] iisexpress.exe" wurde mit Code -2147023895 (0x800703e9) beendet."

The Stacktrace shows null. What am I doing wrong and what can I improve?

I've deleted the "obj" Folder of my Solution and rebuilt the Project and everything works as intended again.