You have upgraded Enforce and detection servers to 15.5.x or above, but a large number of 14.x DLP endpoint agents are still active in your environment.
SEVERE: Agent data batch persist error. Unexpected error occured while agent data being persisted : CallableStatementCallback; uncategorized SQLException for SQL ; SQL state ; error code ; ORA-21525: attribute number or (collection element at index) violated its constraints
This is attributed to large numbers of older agent versions still active in the environment. The workaround is to upgrade the endpoint agents to the 15.x versions as soon as possible.