Incompatible objects

Incompatible objects nothing but Sometimes it is not possible to use certain combinations of objects in data providers. This situation arises when objects bear no relationship to one another. These objects are called incompatible objects.

For example, the Island Resorts Marketing universe contains the
[Reservation Year] and [Revenue] objects, which are incompatible. This is
because there is no revenue associated with a reservation. Revenue is
generated only when the customer is invoiced. The underlying database
structure reflects this; you cannot build a query that aggregates revenue by
reservation year because there is no such thing as revenue by reservation
year. In other words, the aggregation context that you specified for the
[Revenue] object does not exist.