The invoice is sent as email, instead of an attachment (when sent from "find contributions -> actions")
When sending invoices as email from a single contribution, the extension works fine.
However, when I want to do a "mass mail" (i.e. sending to one or more recipients via "find contributions" action menu "send invoice"), there is a strange behaviour:
Instead of using the selected email template for the email, and creating a pdf from the contribution, the mail only contains a pretty broken rendered html of the invoice itself...
This is bad, because it might cause lots of broken invoices sent out.