A bit of background knowledge: I run a small(er) MyBB based forums with plugins for eCommerce. There is a market section in which you can use paypal to buy digital goods. Once you do that, you gain access to the goods. The problem: Sometimes, once you purchase a product (verified it goes through, as I get forwarded the receipts from people) you do not gain access to that product. This is also only for certain products (or maybe buyers). So while some work flawlessly, others never work correctly so everything needs to be done manually. The question: So obviously, the first comment will be to go to the plugin publisher, but alas, he was no help (despite me paying monthly for "customer service"). I guess my question is then, what could be the cause of some payments working and others not? Extra information: The information I was told to use for Paypal IPN does not work either.