How to Troubleshoot and Fix QuickBooks Error H505. QuickBooks Error H505 occurs when a company file on another computer cannot be accessed, typically due to network issues or incorrect multi-user settings. To resolve it, ensure that the hosting settings are correctly configured, verify that both systems are connected to the network, and check for firewall issues blocking access. Updating QuickBooks or performing a fresh installation may also help resolve the error. https://quickbooks-issue.hashnode.dev/troubleshoot-quickbooks-error-h505-in-a-few-simple-steps