You can disable the ViewState for the whole page in the page header:
<%@ Page Language="C#" MasterPageFile="~/Demo.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" ... EnableViewState="false" ... %>
You can also disable it for DayPilot only:
<DayPilot:DayPilotScheduler ID="DayPilotScheduler1" runat="server" ... EnableViewState="false" ... > </DayPilot:DayPilotScheduler>
Since DayPilot Pro for ASP.NET WebForms 6.2 events are not stored in ViewState by default.
You can change the behavior using StoreEventsInViewState property:
It is not recommended to store events in the ViewState because it increases the size of both the request and response and increases the server load.
If you are seeing performance issues, on of the things to try is to disable the ViewState.
If you need to keep ViewState enabled, you can consider compressing the POST requests (Scheduler).
If you disable the ViewState, you need to keep in mind that the property changes will be lost after PostBacks.
You can safely disable ViewState if you are using only CallBack event handling. CallBacks use independent mechanism for synchronization of (selected) DayPilot properties and don't use ViewState information.