One of the items is probably wrong, are your sure about all settings?

Is the hostname correct? be aware of words with capitals

try localhost as host name.

The settings are ok. But your provider doesn't allow direct database access, only from the webserver...

If you change the product quantities on stock "locally on your pc" and want to push them to the database, this doesn't work (PC -> Database).

You can only export your data in CSV, edit the quantities, reimport the data and upload your website as you would have changed stuff.

So this is not the fault of X5, it is very strict settings from your provider. Many providers do that unfortunately. I specifically loof at that setting when choosing a provider.

You could post as an idea that X5 includes stock updates over the /admin utility (as there you can see low stock items already an stock edit function there would be a logical thing).

Thanks Dieter,

Shame that more and more providers close doors, mainly because there are safety issues from people that like to mess things up.

Well, unfortunately only two good options. First is to switch to a provider who allows outside DB access, second would be the product export / update stock in CSV file / import.

Another option: If you are a experienced PHP programmer you could create a protected page in X5 where you add some custome code. This code could fetch your articles from the DB and hold a form where you can update the stock quantities.
I would suggest you only do this if you really know what you do as this is a possible security hole if not programmed well.