# Exceptions¶

 InvalidReference([message, i, b, a, d, …]) Raised when the i-th atom uses an invalid reference. UndefinedCoordinateSystem([message]) Raised when there is no possibility to obtain a defined coordinate system for the chosen construction table. IllegalArgumentCombination Raised if the combination of correctly typed arguments is invalid. PhysicalMeaning([message]) Raised when data is corrupted in a way, that it can not carry any information of physical meaning.