Solution 1 – QuickBooks File Doctor: In any of such very regular error or issue you must consider running a scan from the QuickBooks File Doctor that is there present in your QuickBooks Tool Hub. Also if you don’t have one of these already installed, you must download it from the official website of the Intuit.
Solution 2 – Updating the software: In some cases, the QB experts have found out that the software users don’t update the software to its latest version. You must update the software that sometimes automatically fix all these small issues and errors.
Solution 3 – Updating the Configuration: The error mostly occurs when the software configuration has not been meeting its standard requirements. Changing hardware may help your PC and the software and fix the QuickBooks Error H505.
After applying all these methods restarting the software and the PC is highly recommended.
You can also look for some of the other manual solutions by reading the QuickBooks Error H303 you can apply one of the answers because the errors are of the same series.
If the error persists, consider hiring a QuickBooks Expert available at the QuickBooks Desktop Error Support.