c# – 在asp.net中执行存储过程时出错

执行查询时的错误消息是：传入的表格数据流(TDS)远程过程调用(RPC)协议流不正确.参数1(“@ errMessage”)：数据类型0xE7具有无效的数据长度或元数据长度.

使用代码更新

try
    {
        ...
        ...
        ...
    }
        catch (Exception ex)
        {
            ClientScript.RegisterStartupScript(GetType(),"alert","alert('Email was not sent - " + ex.Message + "');",true);

            string strMessage = ex.Message;
            string strStackTrace = ex.StackTrace;

            strMessage = strMessage.Replace("rn","; ");
            strMessage = strMessage.Replace("   ","");

            strStackTrace = strStackTrace.Replace("rn","; ");
            strStackTrace = strStackTrace.Replace("   ","");
            AppErrorLog(strMessage,strStackTrace);
            return false;
        }


    protected void AppErrorLog(string strErrorMessage,string strErrorStackTrace)
    {
        SqlConnection conErrLog = new SqlConnection(strConn);
        string sql = "usp_AppErrorLog_AddRecord";
        SqlCommand cmdErrLog = new SqlCommand(sql,conErrLog);
        conErrLog.Open();
        try
        {
            cmdErrLog.CommandType = CommandType.StoredProcedure;

            cmdErrLog.Parameters.Add(new SqlParameter("@errMessage",SqlDbType.NVarChar,8000));
            cmdErrLog.Parameters["@errMessage"].Value = strErrorMessage;

            cmdErrLog.Parameters.Add(new SqlParameter("@errStackTrace",8000));
            cmdErrLog.Parameters["@errStackTrace"].Value = strErrorStackTrace;

            cmdErrLog.Parameters.Add(new SqlParameter("@userID",SqlDbType.VarChar,12));
            cmdErrLog.Parameters["@userID"].Value = User.Identity.Name;

            SqlDataAdapter ada = new SqlDataAdapter(cmdErrLog);
            cmdErrLog.ExecuteNonQuery();
        }
        catch(Exception e)
        {
            ClientScript.RegisterStartupScript(GetType(),"alert('AppErrorLog - " + e.Message + "');",true);
        }
        finally
        {
            conErrLog.Close();
        }
    }

表中的列数据类型是nvarchar(MAX).
任何想法如何解决这个问题？