Thanks for following up on LOT. We have switched the data provider for LOT in Azuon 8.0 (to be released soon for Windows too), and these errors should be gone in it.
Hint: If you select LOT as the only airline to search in Azuon and choose one valid route to search, but nevertheless receive an error message "Selected airlines do not operate direct flights between selected origins and destinations", you can fix this error yourself by adding the missing airport(s) to the following page on Wikipedia:
Please take extra care when editing this page as the existing html formatting must be followed closely.
This applies only for LOT. In case you receive the same error for another airline, please report it and we will fix it.