Members profile with all the post they wrote

Hi,

The issue goes like this:
1. On a live support chat, I was told to add Post Indexer to get all of a users post on the users profile page. That worked great, but the site got stuck.
2. On one of my prior support tickets (plugin error) it was explained that that plugin is good only for multisites and doesn't work in single sites - so i got rid of it - and the site worked, but the posts in the user profile disappeared.
3. What should i do?
4. Thanks