Solved

Validation of viewstate MAC failed

Posted on 2007-12-06
4
649 Views
Last Modified: 2012-06-27
This error has just started today, it worked fine as recently as yesterday so I don't know if it was caused by a windows update (last night was weekly server maintenance night which includes updates).
This affects both the production server and my workstation where I develop.

The page loads fine but when I click the edit column on the gridview I get this error:
Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

After Googling I found this page http://forums.asp.net/p/955145/1173230.aspx#1173230
I have done as suggested there which is to add  enableEventValidation="false" viewStateEncryptionMode ="Never" to the page directive but when I do that I get a new error:
Multiple controls with the same ID 'txtStartDate' were found. FindControl requires that controls have unique IDs.

Which is not the case! There is only one control named that, the only other place it is mentioned is for a validatorcontrol which points to this text box as the control to validate.
0
Comment
Question by:QPR
  • 2
  • 2
4 Comments
 
LVL 37

Expert Comment

by:samtran0331
ID: 20429133
can you post your gridview?
0
 
LVL 29

Author Comment

by:QPR
ID: 20452366
Below, let me know if you need the rest of the page code.
As I said working fine up until a particular day and then flop!

 <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource3" CellPadding="4" ForeColor="#333333" GridLines="None" Width="672px" AutoGenerateColumns="False" DataKeyNames="NoticeID">
        <Columns>
            <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
            <asp:BoundField DataField="NoticeID" HeaderText="NoticeID" InsertVisible="False" ReadOnly="True" SortExpression="NoticeID" Visible="False" />
            <asp:BoundField DataField="NoticeText" HeaderText="Notice" SortExpression="NoticeText" />
            <asp:TemplateField HeaderText="StartDate">
                    <EditItemTemplate>
                        <asp:TextBox ID="txtStartDate" runat="server" Text='<%#Bind("StartDate", "{0:dd/MM/yyyy}") %>' />
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="lblStartDate" runat="server" Text='<%#Eval("StartDate", "{0:dd/MM/yyyy}") %>' />
                    </ItemTemplate>
           </asp:TemplateField>
           <asp:TemplateField HeaderText="StartDate">
                    <EditItemTemplate>
                        <asp:TextBox ID="txtStartDate" runat="server" Text='<%#Bind("ExpiryDate", "{0:dd/MM/yyyy}") %>' />
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="lblStartDate" runat="server" Text='<%#Eval("ExpiryDate", "{0:dd/MM/yyyy}") %>' />
                    </ItemTemplate>
           </asp:TemplateField>
            <asp:BoundField DataField="ExpiryDate" HeaderText="Expiry Date" SortExpression="ExpiryDate" />
        </Columns>
        <FooterStyle BackColor="#5D7B9D" ForeColor="White" Font-Bold="True"></FooterStyle>
        <RowStyle BackColor="#F7F6F3" ForeColor="#333333"></RowStyle>
            <EditRowStyle BackColor="#FFFFC0"></EditRowStyle>
            <SelectedRowStyle BackColor="#E2DED6" ForeColor="#333333" Font-Bold="True"></SelectedRowStyle>
            <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center"></PagerStyle>
            <HeaderStyle BackColor="Silver" ForeColor="MidnightBlue" Font-Bold="True"></HeaderStyle>
            <AlternatingRowStyle BackColor="White"></AlternatingRowStyle>
    </asp:GridView>
0
 
LVL 37

Accepted Solution

by:
samtran0331 earned 500 total points
ID: 20452619
>>I get a new error:
>>Multiple controls with the same ID 'txtStartDate' were found. FindControl requires that controls
>>have unique IDs.

In the above, the StartDate column and the ExpiryDate column both have textboxes named "txtStartDate" in their edititemtemplates....

try:

            <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4"
                DataKeyNames="NoticeID" DataSourceID="SqlDataSource3" ForeColor="#333333" GridLines="None"
                Width="672px">
                <Columns>
                    <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
                    <asp:BoundField DataField="NoticeID" HeaderText="NoticeID" InsertVisible="False"
                        ReadOnly="True" SortExpression="NoticeID" Visible="False" />
                    <asp:BoundField DataField="NoticeText" HeaderText="Notice" SortExpression="NoticeText" />
                    <asp:TemplateField HeaderText="StartDate">
                        <EditItemTemplate>
                            <asp:TextBox ID="txtStartDate" runat="server" Text='<%#Bind("StartDate", "{0:dd/MM/yyyy}") %>'>
                            </asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="lblStartDate" runat="server" Text='<%#Eval("StartDate", "{0:dd/MM/yyyy}") %>'>
                            </asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="ExpiryDate">
                        <EditItemTemplate>
                            <asp:TextBox ID="txtExpiryDate" runat="server" Text='<%#Bind("ExpiryDate", "{0:dd/MM/yyyy}") %>'>
                            </asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="lblExpiryDate" runat="server" Text='<%#Eval("ExpiryDate", "{0:dd/MM/yyyy}") %>'>
                            </asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
                <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
                <EditRowStyle BackColor="#FFFFC0" />
                <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                <HeaderStyle BackColor="Silver" Font-Bold="True" ForeColor="MidnightBlue" />
                <AlternatingRowStyle BackColor="White" />
            </asp:GridView>

Open in new window

0
 
LVL 29

Author Comment

by:QPR
ID: 20452654
well spotted thanks!
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

One of the pain points with developing AJAX, JavaScript, JQuery, and other client-side behaviors is that JavaScript doesn’t allow for cross domain request for pulling content. For example, JavaScript code on www.johnchapman.name could not pull conte…
In .NET 2.0, Microsoft introduced the Web Site.  This was the default way to create a web Project in Visual Studio 2005.  In Visual Studio 2008, the Web Application has been restored as the default web Project in Visual Studio/.NET 3.x The Web Si…
This Micro Tutorial will teach you how to censor certain areas of your screen. The example in this video will show a little boy's face being blurred. This will be demonstrated using Adobe Premiere Pro CS6.
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, just open a new email message. In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…

813 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now