"Failed to crawl content source" – Search couldn't crawl a specific content source.

If SharePoint fails to crawl a specific content source, it means that the Search Crawler cannot access the content repository, preventing new items from being indexed and appearing in search results. This issue can arise due to misconfigurations, permission issues, connectivity problems, or crawl component failures.

Below is a step-by-step troubleshooting guide to diagnose and resolve the issue.

Step 1: Identify the Error in Crawl Logs

The first step is to check for detailed error messages in the Search Crawl Logs.

Open Central Administration.
Navigate to Manage Service Applications.
Click on Search Service Application.
Under Crawling, click Crawl Log.
Look for the content source that failed and check for specific error messages such as:
- Access Denied – Permission issue.
- Timeout Errors – Network or server issue.
- URL Not Found – Incorrect URL configuration.
- Content Source Not Available – Corrupted or deleted content source.

Take note of the error and proceed to the next steps to resolve it.

Step 2: Verify Content Source Configuration

Incorrectly configured content sources can cause crawl failures.

Open Central Administration.
Go to Search Service Application > Content Sources.
Check if the content source URL is correct.
- If crawling a SharePoint site, the URL should be in the format: http://yoursharepointsite/
- If crawling a file share, ensure the URL follows this format: file://yourserver/sharedfolder/
If the URL is incorrect or inaccessible, edit the content source and update the URL.

Step 3: Check Crawl Account Permissions

The Crawl Account must have read access to the content source.

3.1: Verify SharePoint Site Permissions

Open the SharePoint site being crawled.
Click on the gear icon and go to Site Settings.
Under Users and Permissions, click Site Permissions.
Ensure that the crawl account (e.g., DOMAIN\SP_Crawl) has at least Read access.
If missing, grant the permissions manually and try crawling again.

3.2: Verify File Share Permissions (If Crawling a File Server)

Open the file share location (e.g., \\server\sharedfolder).
Right-click the folder and select Properties > Security.
Ensure the crawl account has:
- Read & Execute
- List Folder Contents
- Read
If missing, add the crawl account and assign these permissions.

3.3: Verify Database Permissions (If Crawling External Data)

If crawling external content (e.g., databases), ensure that:

The crawl account has DB_DATAREADER access.
The content source connection string is correct.

Step 4: Ensure the Search Crawl Component is Running

A failed crawl can also be due to search components not functioning properly.

Open Central Administration.
Click Manage Service Applications > Search Service Application.
Navigate to Search Administration.
Under Search Components, ensure that:
- Crawl Component is running.
- Query Processing Component is healthy.
If any component is in a failed state, restart the search service.

4.1: Restart Search Service

If components are malfunctioning, restart them:

Restart-Service -Name OSearch15 -Force

After restarting, check if crawling resumes successfully.

Step 5: Perform a Manual Full Crawl

If search failed to crawl content, forcing a full crawl may resolve the issue.

Open Central Administration.
Go to Search Service Application > Content Sources.
Select the affected content source.
Click Start Full Crawl.
Monitor the Crawl Log for any errors.

Step 6: Check and Reset Search Index

A corrupted search index can prevent successful crawling.

6.1: Reset the Search Index

Open Central Administration.
Go to Search Service Application > Index Reset.
Click Reset Now.
After resetting, start a Full Crawl.

⚠️ Warning: Resetting the index will delete all indexed data and require a fresh full crawl.

Step 7: Check ULS Logs for Additional Errors

If crawling still fails, check the ULS logs for more detailed error messages.

Open SharePoint Management Shell.
Run the following command to filter search-related logs:

Get-SPLogEvent | Where-Object { $_.Category -eq "Search" } | Select-Object -First 20

Look for any critical errors related to crawl failures.

Step 8: Verify SQL Server and Database Health

If search is crawling SharePoint content but failing, SQL Server issues may be involved.

Open SQL Server Management Studio (SSMS).
Check the Search Crawl Database (Search_Service_Application_CrawlStore).
Ensure the crawl account has:
- DB_OWNER
- DB_ACCESSADMIN
Run the following query to check database health:

SELECT name, state_desc FROM sys.databases
WHERE name LIKE 'Search%'

If any database is in a “SUSPECT” or “OFFLINE” state, repair it before retrying the crawl.

Step 9: Verify Firewall and Proxy Settings

If crawling external content sources (e.g., file shares, web pages, databases), firewall or proxy settings might be blocking the crawl.

Open Windows Firewall > Advanced Settings.
Ensure that the following ports are open:
- TCP 1433 (SQL Server)
- TCP 8080 (SharePoint Web Apps)
- TCP 32843, 32844 (Search Components)
If using a proxy, ensure that the crawl account has proper access.

Step 10: Recreate the Search Service Application (If Needed)

If all else fails, consider recreating the Search Service Application.

10.1: Delete the Existing Search Service Application

Open Central Administration.
Go to Manage Service Applications.
Select Search Service Application and click Delete.

10.2: Create a New Search Service Application

Open Central Administration > Manage Service Applications.
Click New > Search Service Application.
Enter:
- Service Name (e.g., Search_Service_New).
- Service Account (Select an existing or create a new one).
Click OK and perform a Full Crawl.

Step 11: Restart SharePoint Server

If search is still failing to crawl content, restart the entire SharePoint server.

Restart-Computer -Force

After restarting, verify the crawl status using:

Get-SPEnterpriseSearchServiceInstance

“Failed to crawl content source” – Search couldn’t crawl a specific content source.