Seen in DX NetOps Performance Management OI Connector OIConnector.log files. They flood the file with thousands of entries.
[ERROR] 2022-02-23 14:38:45.732 [pool-3-thread-12] InventoryTaskImpl - [EVENT FAILURE Anonymous:@unknown -> /NetOps OI Connector/com.ca.im.oinet.connector.task.inventory.InventoryTaskImpl] Exception occurred while processing the null data
All supported DX NetOps Performance Management releases
Interfaces contributed to Data Aggregator inventory without an associated parent device.
A fix has been added starting with the DX NetOps Performance Management OI Connector that comes with release 21.2.9 via defect DE529280.
Upgrade to that release or newer to obtain a resolution.
Sometimes a Full Data Aggregator synchronization cycle helps resolve the unparented interfaces and clears up the errors.