What is the issue?
Error while doing order match that "No purchase orders found that could be associated with the invoice" even if the order is available and meet the association rules.
If the order is available and association rules are matching then need to check the time of the order created (If we are using P2P Purchase).
If Matching happens within few seconds to a couple of minutes from the order creation time then order cannot be matched as order created in Basware becomes available for matching after 2-3 minutes of order creation timestamp.
NOTE: This article is valid only if we are using P2P Purchase for creating orders and is not valid if we are importing orders.