Thought I'd share these, since I searched the thread and don't see this error code.
Trying to search for AMS-BER (also tried TXL, but error appears to be related to origin)
There are no scheduled Delta/Partner flights from null (ZYA). Please try searching for airports within a 100 mile radius of null (ZYA). #101765RR
KRK-AMS
There are no scheduled Delta/Partner flights from John Paul II Balice Intl (KRK). Please try searching for airports within a 100 mile radius of John Paul II Balice Intl (KRK). #101765RR
The flights definitely exist on the same dates with KLM, and there's no problem finding them on the KLM site.