Could not retrieve profile schema from server

How many of you faced this strange behavior of SharePoint 2013 designer?

When trying to use User Profile as a Data Source in a workflow. Something similar to the screen shot below:

Try looking in google did not give me the expected solution. A lot of people suggested to grant permissions of the web app pool account to the search service database. But what actually that means? I granted read permissions to all search related databases, but as you expect the problem was still persisting.

So many articles were referring to Search I was start thinking that the problem is really there. But all of the explanations were not exactly correct. The right way to make it working is:

1. Go to Central Admin
2. Go to Manage Service Applications
3. Select Search Service Application, but don't click on it
4. Select Administrators
5. Add the application pool account of the web application
6. Grant "Read (Diagnostic Pages Only)" permission and click OK

Afterwards everything should work normally.

For now I don't have exact explanation why these settings are necessary. Will try to find out and post here as a comment.