After creating My Site when the user try to Click on "Newsfeed" or any my site related features.we are getting the error "Could not load user profile",based on the error message we can able to identify that user profile service application is not connected with that web application in most of cases we will the issues in all the site collections and its sites.
In my case Issue resolved follow the steps
Click on the Appliction Proxy Group->default->Uncheck the User Profile Service Application Click ok.
Again Check the User Profile Service Application Click ok.
Now check it will works,if still we are getting the same issue wait for few minutes and try again.
If this issue not yet resolved, go the user profile service application check weather we can able to access the user profile with out any issues.