VM child categories

How can I create a coupon, that calculates discount for a VM product categorie and all its child en grandchilds categories?

Hello,

Category coupons do not apply to children categories. There are 2 options to get this working:
1) select the category and all the children categories when creating the coupon
2) Add each product in the category/child category to a single category and select that category when creating the coupon

OK, i will add the child categaories. Next issue I run into, that the coupon is only recognized after the customer is logged in, but I want this coupon to also be available to new users who are not logged in yet.
It seems to make no difference if I clear the customer(group) selection.
How do I do this?

If you set the number of uses to x per customer, the user is required to log in also to verify they are eligible. You can update the error code in awocoupon->configuration->error code tab to something like 'Please log in to use this coupon'.