IssueThe search service is not able to connect to the machine that hosts the administration component. Verify that the administration component ‘GUID’ in search application ‘Search Service Application’ is in a good state and try again
In Farm Search Administration page when you click on “Modify Topology” you get error “An unhandled exception occurred in the user interface.Exception Information: Exception has been thrown by the target of an”Search is not able to connect is because of many reasons, In this article I am providing all possible causes and the solutions.
In the end it turns out to be that the application pool that hosts the search service application somehow doesn’t have the correct access.
You can simply change the application pool to use SharePoint Web Services System for search service applications and check.
1. Click on Start > Run > Type Inetmgr > Click OK