We are on SharePoint 2016 Server.
I am receiving a message when I try to search "Unexpected response from server. The status code of response is '404'. The status text of response is 'Not Found'."
I also receive a "Sorry, we're having trouble reaching the server" message when I try to grant someone permissions to the site.
Our Search Service Application is running in Central Administration. I do not see any errors.
Also when we use SharePoint Designer 2013 we receive a message that says SharePoint Foundation not installed.
Could someone please help with suggestions.