When I open the Experience Profile tab on my Sitecore 9.1.1, I get an error: An error has occurred.

In Chrome console: Failed to load resource: the server responded with a status of 500 (Internal Server Error) --/sitecore/api/ao/v1/contacts/search?&pageSize=20&pageNumber=1&sort=visitCount%20desc&Match=*&FromDate=null&ToDate=null:1

On opening that api uri, getting '{"Message":"The requested resource does not support http method 'GET'."}'

Verified XConnect running, solr url without # and Newtonsoft.Json.dll version.