Please ensure that you entered the correct name of your business, and the correct VAT number (including the two letters for the country code at the beginning).

You can also check if it is valid on the VAT site of the European Commission (fill the first two boxes on that page). There you can also double check under which name your business is registered. Please use that as business name when you enter it on our site.

If it shows as invalid on there also, please have a look at this section (or this section in German) to see possible causes.

This means your server has difficulties communicating with our server. In most cases the reason for this is that there are restrictions on outgoing connections on your server, e.g. because of a firewall. Please ask your hosting company / server team to either a) temporarily de-activate the firewall (port 443) for a minute (at least the outgoing connections) or b) whitelist 188.165.53.179 and 192.81.249.240 as IPs so that your server can communicate with our server.

Please:

1.) Install the plugin on the parent site but do not activate it

2.) Activate it on the child site where you want to use it

Please ensure that:

• You do not still have the PLUS version installed (please delete it entirely from your system)
• You are using the latest version of the plugin(s)
• Your site is running on PHP 5.4 or above 
• You have CURL activated (should be activated by default)

If you are not familiar with those, please contact your hosting company or server admin.

Please check if you have browser extensions activated which may conflict with the plugin. Known culprits include:

• Open SEO Stats (Formerly: PageRank Status) – Chrome
• Adblock Plus – Chrome
• Vine – Chrome
• Optimizer.io
• RegistrationMagic
• Woo Order Note template

Either de-activate those extensions or try it in a different browser.

Please have a look at this list.