Prerequisite 1. Check if People Search Application is installed

1. Open SharePoint Central Administration.

2. Choose Applications Management.

2. Click Manage Service Applications.

3. Search Service Application must be there:

If Search Service Application is not in the list, please do the following сreate and configure a Search Service Application.


Prerequisite 2. Check if Managed Metadata Service is installed

1. Open SharePoint Central Administration.

2. Choose Applications Management.

2. Click Manage Service Applications.

3. Managed Metadata Service must be there:

If Managed Metadata Service is not there, please check this article.


Prerequisite 3. Check if Search Center Site is Configured

1. Open your root site.

2. Add /search to the URL of your root site (type it into the address bar of your browser).

3. You should see the following:

If you don't see a page with a search bar like this, please create a Search Center Site.


Prerequisite 4 (for SharePoint 2013 only). User and Group Profiles Should be Synchronized

If this is not yet done, please synchronize the User and Group Profiles as explained in this article.