Latest incarnation of the Schrödinger Cat Paradox forces a new view of quantum theory

A recent paper by Frauchiger and Renner has brought to light a serious problem with  conventional approaches to quantum theory, by deriving a contradiction using those approaches. In  FR Paradox Kastner 10.17.19  I argue that the paradox shows that quantum theory leads to absurdities and inconsistencies unless there is a clear physical criterion for ‘measurement’.  Published version here: https://link.springer.com/article/10.1007/s10701-020-00336-6