QuickBooks Error Code H303 sometimes occurs because your firewall is blocking the software. You can refer to the steps given below to change the setting and resolve the issue:
• Step 1: Switch on your computer and go to the Control Panel.
• Step 2: Click on the ‘Settings’ option and select your Firewall Settings.
• Step 3: Select the ‘Allow a Program’ option choose ‘Add Program.’
• Step 4: Add your QuickBooks software to the exception list.
• Step 5: Save the changes and restart your device.

If you find that the error continues then you can call the QuickBooks contact number and speak to a professional software technician to fix the issue.

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