Problem: You attempt to configure search scope settings for a site collection and the following error appears in the Unified Logging Service (ULS) on a web front-end (WFE) server (I've removed some of the stack trace for brevity):

Microsoft.Office.Server.Search.Query.Search
ServiceNotFoundException: The search request
was unable to connect to the Search Service.at Microsoft.
Office.Server.Search.Internal.UI.Search
AdminPageBase.ErrorHandler(Object sender,
EventArgs e)...

One Possible Reason For This Error: A search service application has been created, but it is not associated with the Web Application containing the site collection where you're attempting to configure search scopes.

Solution using the UI:

1. Navigate to Central Administration, Application Management, Configure service application associations.

2. Click the Application Proxy group associated with your target Web Application (typically the default Application Proxy Group).

3. If the new Search Service Application proxy check box is not selected, select it to associate this service with your Web Application.

4. Navigate to the target site collection where accessing Search Scopes is failing.

5. Navigate to Site Settings, Search Scopes for the target Site Collection. If another error message appears stating that an indexer move might be in progress or the search service isn't running, then reset the Index in Central Administration by following the next step:

6. Navigate to Central Administration, Manage Service Applications, and click your search service application. The default name is "Search Service Application."

7. Click Index Reset, then click Reset Now.

8. Attempt to view and configure the scopes again in the Site Settings of the target Site Collection.

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