Project creation is failing via XOG.
APP log error:
Caused by: java.sql.SQLException: [CA Clarity][Oracle JDBC Driver][Oracle]ORA-01502: index 'CLARITY.PAC_MNT_PROJECTS_U1' or partition of such index is in unusable state
Release : 16.0.0
The error indicates the specified index needs to be rebuilt.
Have the DBA team rebuild the index specified in the APP log.
Oracle Support will need to be contacted directly for issue prevention as it could be related to the configuration/parameters, e.g parameter skip_unusable_indexes
The Oracle Alert logs should have more information and can be provided to Oracle Support for confirmation and recommendations on how to manage the database so that the error can be prevented.