Is anyone else getting an Uncaught Exception... looks like an SQLite Error of some description... but no idea what is causing it?

Uncaught exception: Error: Error: SQLITE_CONSTRAINT: FOREIGN KEY constraint failed INSERT INTO unit_authors (unit, address, definition_chash) VALUES(?,?,?) FDIOwPxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxO2/yE=, HZTYxxxxxxxxxxxxxxxxxxxxxxxxxxxxxCUE,
