The frame receivers report this error in the dev deployment. It seems to be harmless and acquisitions run as expected. I am not sure why it says frame -1. Maybe this is a simulator issue. Check if it happens with a real detector.
/odin/eiger-detector/cpp/data/frameReceiver/src/EigerFrameDecoder.cpp:487:
12:38:02,893 FR.EigerFrameDecoder ERROR - Frame data detected but no free buffers available. Dropping data for frame -1