MSIR.0754 Class (class), (method): not (action)
The indicated method was used in a context in which it's not allowed. If the object is a member of a system class, check the method documentation to determine its appropriate contexts. If the object is a member of a User Language class, determine if the attempted action is reasonable. A common mistake is to forget to specify a function that returns an informational value as Callable, If a function performs meaningful processing other than determining its result value, it probably makes sense to make it Callable.