I placed a cache signalum on a doubled Quick Sort module pipe.

The game crashed whilst ticking block entity
Error: java.lang.UnsupportedOperationException: Couldn't extract the already sended items from the inventory.

crash-2019-06-19_18.36.18-server.txt

Cannot reproduce with the most recent build. Can you re-test and if the crash still happens, upload a screenshot and a description of your pipe connecting to the buffer?