How can I troubleshoot the SmartTube Next 403 error related to a specific website?

First, verify the website's availability – is it down for everyone or just you? Then, check your SmartTube Next settings for that specific source. Ensure the URL is correct and that you haven't accidentally blocked it. Try clearing the cache and cookies in SmartTube Next. If still failing, try a different VPN server (if using one) or temporarily disable it to see if that resolves the issue.