SharePoint 2013 No Results in Doing Searches

Hello,

I have a customer who says she cannot find any results doing a search on her site. I tested other sites and I get the same response whether it be for a document name or a piece of data in a list.

I do a search and I get this message:

Your search returned no results.

Some items might be hidden. Include these in your search

I click "include" and I get this message:

You search returned no results.

Still didn't find it? Try searching the entire site.

I click "entire site" and I get this message:
Results found in Enterprise Infrastructure Systems

Nothing here matches your search
Suggestions

Make sure all words are spelled correctly
Try different search terms
Try more general search terms
Try fewer search terms
Try these tips for searching

Here are the steps I have taken so far:

1) Verified each server in our environment has running services.

2) Started Central Administration, under Search Administration, I went to Search Schema and went to ListItemID. There I checked the box to make it searchable. No change.
3) I initiated Full Crawls on Local SharePoint sites and projects. No change.
4) Restarted the SharePoint servers (SQL first then five minutes later others) no change

Appreciate anyone that has read this or has ideas for me to try.