Only process instances whose process type has a registered indexed dimension are included in an index.
If an indexed dimension is registered or deregistered at a process tree node (at a later time), these process instances are missing from the index or are too many. The index can therefore no longer be used until regenerated. Only with the next import or restart, when all indices are regenerated, the index is then available again.
For this reason, all indices are set to "invalid" when certain configurations of dimensions in the process tree are changed. Changes to the configuration which result in the indices being set to "invalid" are: