Hello there, @alvis. I’m here to share additional troubleshooting steps to resolve Error Code 80040408 in QuickBooks Desktop (QBDT).

Step 1: Update QuickBooks Web Connector:

• Ensure that QuickBooks Web Connector is up to date by downloading and installing the latest version from the Intuit website.
• Uninstall any existing versions of QuickBooks Web Connector before installing the new version.

Step 2: Check Web Connector Configuration:

• Open QuickBooks Desktop and navigate to the Edit menu.
• Select Preferences, then Integrated Applications, and click on the Company Preferences tab.
• Verify that the third-party application or service is listed and enabled in the list of integrated applications.
• If the application is not listed or enabled, follow the instructions provided by the application provider to reconfigure the integration settings.

Step 3: Review Firewall Settings:

• Check your firewall settings to ensure that QuickBooks Web Connector and the third-party application are allowed to communicate through the firewall.
• Add QuickBooks Web Connector and the third-party application to the list of trusted applications or exceptions in your firewall settings.
• Consult your IT administrator or refer to the documentation for your firewall software for assistance with configuring firewall settings.

Step 4: Test Network Connectivity:

• Verify that your computer has a stable internet connection and can access the external application’s website or services.
• Test network connectivity by pinging the server hosting the third-party application to ensure there are no network issues.

Step 5: Reset QuickBooks Web Connector:

• Close QuickBooks Desktop and open the QuickBooks Web Connector application.
• Select the third-party application or service experiencing Error 80040408 and click on the Remove button to remove it from the Web Connector.
• Re-add the application by clicking on the Add Application button and following the on-screen instructions to set up the integration again.

Step 6: Contact Application Provider Support:

• If Error 80040408 persists after following the above steps, contact the support team of the third-party application or service for further assistance.
• Provide them with details about the error and steps you’ve taken to troubleshoot it, as they may have specific troubleshooting procedures or updates to resolve the issue.