Error 'Failed to send request' or unable to login with Data Loader

1. Check the server host: You'll want to make sure that the server host has been set to https://login.salesforce.com or if you're using sandbox, the URL is https://test.salesforce.com. Please review, Configure Data Loader.


2. Check your instance: If you're unable to connect via the generic server hosts in step 1, try connecting to your instance directly via: https://<InstanceHere>.salesforce.com where <InstanceHere> is the Salesforce instance that is hosting the organization. See Find your Salesforce Organization ID for more details on identifying which instance your org resides on.

Please review, View instance information for your Salesforce organization.


3. Check if your network is using a proxy: Getting the error message, "Failed to send request to https://www.salesforce.com/services/Soap/u/31.0" typically indicates that you're going through a proxy server resulting in your login attempt from the Data Loader not making it from your local machine to Salesforce servers. If your network is utilizing a VPN, you'll need to include or set your proxy information in the Data Loader settings. We recommend contacting your IT department to get the following pieces of information:

• Proxy host
• Proxy port
• Proxy username
• Proxy password settings

4. Check network connectivity or local machine issues: Review the affected user record's login history. Please review, Monitor Login History. If the Data Loader's login attempt has been recorded, you'll want to check the login attempt status. You'll be looking for login attempts that failed due to:

• Incorrect password
• Login restrictions
• Missing a required security token (Please review, Reset Your Security Token).

If a login attempt is recorded as successful, check with your Network team to ensure that they have added Salesforce IP Addresses and Domains to Allow to your network setup (For example, firewalls, switches, routers, etc.).
 

5. Check the port availability - Data Loader connects using standard HTTPS port 443.
If no login attempt has been recorded, check that the correct username and server host setting is being used. Once you've confirmed that all information is correct, and you're still not seeing a login attempt recorded, check your firewall, router, switch, or other network related devices. Please review, Troubleshoot network performance issues with ping and traceroute.

If you continue to experience trouble with the Data Loader, you'll want to try uninstalling and reinstalling the latest version found via Setup | Data Management | Data Loader. Alternatively you may consider Install Data Loader on another machine to rule out any local machine issues.

To see this information in video format, watch How to Troubleshoot Error 'Failed to Send Request' or 'Unable to Login with Data Loader'.


See also
Why can’t I log in to Data Loader?

Data Loader OAuth 2.0 Device Flow Removal

Support Videos:
How to Troubleshoot Error 'Failed to Send Request' or 'Unable to Login with Data Loader'
How Can I Find My Security Token and Use It in Data Loader