Hi ,

I created new data type:

public object value
        {
            get
            {
                return drop1.SelectedValue;
            }
            set
            {
                drop1.SelectedValue = value.ToString();
            }
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            if (Page.IsPostBack)
            {

            }
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string dropDownValue = string.Empty;
            dropDownValue = value.ToString();
            Label1.Text = "You have selected this" + dropDownValue;
        }

Every time that I publish the node I recieve the next error:

 Conversion failed when converting date and/or time from character string. 

             Description: An unhandled exception occurred during 
the execution of the current web request. Please review the stack trace 
for more information about the error and where it originated in the 
code.

             Exception Details: System.Data.SqlClient.SqlException: Conversion failed when converting date and/or time from character string.

[SqlException (0x80131904): Conversion failed when converting date and/or time from character string.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +1742110
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5279619
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +242
   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +1434
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +269
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) +1355
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +175
   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite) +205
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +160
   Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(SqlConnection connection, CommandType commandType, String commandText, SqlParameter[] commandParameters) +56
   Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters) +78
   umbraco.DataLayer.SqlHelpers.SqlServer.SqlServerHelper.ExecuteNonQuery(String commandText, SqlParameter[] parameters) +18
   umbraco.DataLayer.SqlHelper`1.ExecuteNonQuery(String commandText, IParameter[] parameters) +79

[SqlHelperException: Umbraco Exception (DataLayer): SQL helper exception in ExecuteNonQuery]
   umbraco.DataLayer.SqlHelper`1.ExecuteNonQuery(String commandText, IParameter[] parameters) +134
   umbraco.cms.businesslogic.datatype.DefaultData.set_Value(Object value) +727
   umbraco.editorControls.userControlGrapper.usercontrolDataEditor.Save() +60
   umbraco.controls.ContentControl.saveClick(Object Sender, ImageClickEventArgs e) +149
   umbraco.controls.ContentControl.savePublish(Object Sender, ImageClickEventArgs e) +20
   System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +115
   System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) +124
   System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint

What could be the reason?

Thanks,

kukuwka