I did not use any proxies at all
It also gets stuck at Testing XML-RPC before giving any errors
If it doesn't even make it past testing xml-rpc and your not using proxies, then it seems its getting stuck there due to something messing with the connection. Or I suppose it could be the end site. Firstly though make sure you have scrapebox and the article plugin set as trusted/allowed in all anti-virus, malware checkers, firewalls etc... all security software.
Next you can try disabling the router firewall and whitelisting scrapebox and the addon in your router.
Also you can try shutting down any unneeded programs to make sure utorrent, skype etc... isnt interfering.
As Sweetfunny noted, your errors aren't coming from the plugin, 404 is not found, so that would mean the proxy or the end site isn't found.
407 is a authentication needed, that is almost certainly coming from your proxies.
403 is forbidden and I would presume thats from your proxies, but could be from security software, the end site, etc...
So i bought Scrapebox today, and i start to learn from it.
My first really problem is : my whole fucking list of proxies are kick by scrapebox >_<
So, i find i can harvest many proxies and test it.
The proxies who are google passed are good or not ? And, the fact i test many proxies (like 25k or more), my internet provider can be "angry" on me ?
And thanks for your tutorial, i have trouble to understand it by the fact i have low skill english but you have a good speaking, so it's cool =)
Your proxies are kick by scrapebox - what exactly does that mean? That they were all bad when tested?
Google passed proxies are both anonymous and will work with google, at least for basic keyword scraping. Non google passed proxies that are still anonymous can be used for anything else besides google, although posting is ideally done with private proxies.
As for your ISP, that will vary. If there are no limits to your usage by your ISP, they probably wont' care, but really you would have to ask. You could come up with some creative story and call them up. Or just get a VPS.
I presume you meant my vids, glad they are helpful. I only know pieces of other languages, none good enough to build tutorial videos in. Good luck and stick with it, you will get it.