I faced a problem like, when I search for some content, the result is not bringing me the content from one specific web application. The result fetches from all other web applications. But not from one web application. On the process of debugging, I found some interesting stuff. Thought of sharing with the sharepoint community.
First thing, verify the Crawl Log. On the crawl Log, I found some exception like, there is no access for the SPSearch Service Account to the Web Application.
At that time, we need to give access to the SPSearch Service Account on the Web Application.
Go to Central Administration
Click on the Manage Web Applications
Select the web application and Click on User Policy.
The below screen will be appearing.
On that, Add Users. Select the Zone as Default.
Add the user SPSearch with full Control.
That’s it. Now we gave permission for the SPSearch Account to the WebApplication.
Then come back to the Registry. There we need to do a small modification.
1. Once opened the registry editor, just navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa"
2. Right click on "Lsa" and create a new 32bit DWORD value
3. Rename it as "DisableLoopbackCheck" (Note: you cannot rename it actually. so, once created the DWORD value, directly paste/type as "DisableLoopbackCheck".
4. Then again modify the value of "DisableLoopbackCheck" as "1"
Close the registry editor.
Do an IISRESET.
Now start to crawl the content.
Now, the content from that WebApplication should appear on your Search Results. This will be really helpful, when trying to implement the Cross Site Publishing Concept in SharePoint 2013.