Cause
This error occurs if you have defined a key path that has a component that does not have an inverse to its prior component.
When a collection with key paths participates in a relationship (that is, a reference of the collection type is used as an inverse), the following applies.
Except for the first component in a key path, each class on which every subsequent component is defined must have at least one property that is an inverse to the previous component in the key path.
If this is not the case, an error occurs when the offending class is opened.
Consider the following example.
class Person reference myEvent of type Event class Event attribute timestamp of type Timestamp member key dictionary PersonByEventDict membership Person key path myEvent.timestamp
In this example, accessing an instance of Person or Event (thereby opening its class) would result in a 1099 - Key path component does not have an inverse to its prior component exception because there is no property on Event that is an inverse of the myEvent property on Person. The timestamp component of the key path is therefore missing an inverse to its prior component, myEvent. In this case, the solution is to ensure that myEvent on Person has at least one inverse on the Event class.
Action
For each component of the key path (except for the first), ensure that the class on which it is defined has at least one inverse to the prior component in the key path. If this is not possible, you cannot use a key path in this case.