Compilation Error in Diagnostic Page in Sitecore 7.5 and 8.0

Coveo for Sitecore 5 (December 21, 2018) Coveo for Sitecore 5 (June 13, 2019)

Symptoms

When trying to access the Coveo Diagnostic Page, you get an error like the following:

Server Error in '/' Application.
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
Compiler Error Message: CS1061: 'Coveo.SearchProvider.Applications.Admin.SecurityDetails.SecurityProviderDetails' doesn't contain a definition for 'IsExpandedPermissionsProvider' and no extension method 'IsExpandedPermissionsProvider' accepting a first argument of type 'Coveo.SearchProvider.Applications.Admin.SecurityDetails.SecurityProviderDetails' could be found (are you missing a using directive or an assembly reference?)
Source Error:
Line 115:                            <td><%# Item.SecurityProviderName %></td>
Line 116:                            <td>
Line 117:                                <%# Item.IsExpandedPermissionsProvider ? "Yes." : "No." %>
Line 118:                                <asp:Label Visible="<%# Item.ShouldUpdateToExpanded %>" runat="server">
Line 119:                                    This instance is still using Sitecore 2 Security Provider. To upgrade, click

Cause

When correcting a bug in the December 21, 2018 version of Coveo for Sitecore, code in the Sitecore 7.5 and Sitecore 8.0 specific CoveoDiagnosticPage.aspx page was not properly removed.

Resolution

The issue is resolved in the June 18, 2019 release of Coveo for Sitecore. You can fix the problem by upgrading to this release.

Workaround

You can delete the excess code from the CoveoDiagnosticPage.aspx page.

1. Open the [Your Sitecore Instance]\Website\sitecore modules\Web\Coveo\Admin\CoveoDiagnosticPage.aspx file in a text editor.

2. Locate and delete the code block below.

   <asp:PlaceHolder ID="SecurityProviderSection" runat="server">
       <asp:Repeater ID="SecurityProvidersDetailsSection" ItemType="Coveo.SearchProvider.Applications.Admin.SecurityDetails.SecurityProviderDetails" runat="server">
           <HeaderTemplate>
               <table cellspacing="0" class="coveo-states published-items">
               <thead>
               <tr>
                   <th>Security Provider Name</th>
                   <th>Is Expanded Permissions Provider</th>
                   <th>State</th>
               </tr>
               </thead>
               <tbody>
           </HeaderTemplate>
           <ItemTemplate>
               <tr>
                   <td><%# Item.SecurityProviderName %></td>
                   <td>
                       <%# Item.IsExpandedPermissionsProvider ? "Yes." : "No." %>
                       <asp:Label Visible="<%# Item.ShouldUpdateToExpanded %>" runat="server">
                           This instance is still using Sitecore 2 Security Provider. To upgrade, click
                           <a href="https://developers.coveo.com/x/nYQkAg" runat="server">here</a>.
                       </asp:Label>
                   </td>
                   <td><%# Item.FetchingStatus %></td>
               </tr>
           </ItemTemplate>
           <FooterTemplate>
               </tbody>
               </table>
           </FooterTemplate>
       </asp:Repeater>
   </asp:PlaceHolder>
   <asp:Label ID="SecurityProviderErrorMessage" Visible="false" runat="server"/>
   

3. Save your changes.