ASPxHiddenField - It is impossible to get the Generic List<T> from the hidden field

According to this: https://documentation.devexpress.com/#AspNet/CustomDocument5762 the ASPxHiddenField supports all lists that implements the IList interface.

I created the following class in order to use a List<logItem> of them and pass it to the ASPxHiddenField, but when I try to use it the application throws an error. I had to implement a string representation of the objects and created a list of type: List<string>, using this approach I'm able to send and receive the List<string> using the ASPxHiddenField.

¿Is this the only way or can I use directly the List<logItem> object with the ASPxHiddenField?

C#
public class logItem  
    {  
        public int errorCode { get; set; }  
        public string key { get; set; }  
        public string Description { get; set; }  
        public DateTime timeStamp { get; set; }  

        public logItem(int _errorCode, string _key, string _Description)  
        {  
            this.errorCode = _errorCode;  
            this.key = _key;  
            this.Description = _Description;  
            this.timeStamp = DateTime.Now;  
        }  

        public logItem(string rep)  
        {  
            var arr = rep.Split('|');  

            errorCode = int.Parse(arr[0]);  
            key = arr[1];  
            Description = arr[2];  
            timeStamp = DateTime.Parse(arr[3]);  
        }  

        public override string ToString()  
        {  
            return string.Format("{0}|{1}|{2}|{3}", errorCode, key, Description, timeStamp);  
        }  
    }  

//-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_  

//Trying to use the ASPxHiddenField  

                System.Collections.Generic.List<string> errorsList = new System.Collections.Generic.List<string>();  

                //Changed to string representation  
                errorsList.Add(new UserControls.logItem(1, "mat1", "material 1").ToString());  
                errorsList.Add(new UserControls.logItem(2, "mat2", "material 2").ToString());  
                errorsList.Add(new UserControls.logItem(3, "mat3", "material 3").ToString());  

                ASPxHiddenFieldErrors.Set("ErrorsList", errorsList);  

//-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_  

//Reading the ASPxHiddenField  
var param = (List<string>)hiddenFieldErrorList.Get("ErrorsList");