Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Validation of viewstate MAC failed

Posted on 2007-12-06
4
Medium Priority
?
659 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
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 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 2000 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

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

This article discusses the ASP.NET AJAX ModalPopupExtender control. In this article we will show how to use the ModalPopupExtender control, how to display/show/call the ASP.NET AJAX ModalPopupExtender control from javascript, how to show/display/cal…
Introduction This article shows how to use the open source plupload control to upload multiple images. The images are resized on the client side before uploading and the upload is done in chunks. Background I had to provide a way for user…
Video by: ITPro.TV
In this episode Don builds upon the troubleshooting techniques by demonstrating how to properly monitor a vSphere deployment to detect problems before they occur. He begins the show using tools found within the vSphere suite as ends the show demonst…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…

604 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