This error can occur due to the Firewall blocking the outgoing and incoming communication. To resolve QuickBooks Error h505 follow these points.
Go to the ‘Control Panel.’
Search Firewall Settings. Click it and choose ‘Allow a Program through Firewall.’
Tap ‘Add Program’ and then on ‘Add QuickBooks 20xx to the exception list.’
Restart your device. https://www.quickbak.com/quickbooks-error-h505