Running UpgradeWebCenterPortal WLST Command To Upgrade WebCenter Portal to 12c Fails with Error Upgrading pageStyle: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (PORTAL_WEBCENTER.IX_UNIQUE_PORTA_NAMESPACE_NAME) violated (Doc ID 2744015.1)

[TRACE]: Data migration from MDS to database could not be completed successfully. Review the log files for details to fix the errors, and run the upgrade again to migrate the failed portals/portal templates.
[TRACE]: Exiting class: LifecycleHandler, method: _doMDSToDBDataMigration

[TRACE]: Failed to upgrade WebCenter Portal application.

[TRACE]: Exiting class: Lifecycle, method: upgradeWebCenterPortal

[<DATE-TIME>] [WC_Spaces] [ERROR] [WCS-73003] [oracle.webcenter.upgrade.framework.UpgradeManager] [tid: [ACTIVE].ExecuteThread: '35' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: <userId>] [ecid: <Ecid>] [APP: webcenter] [partition-name: DOMAIN] [tenant-name: GLOBAL] Upgrade failed for portal Scope[name=defaultScope, guid=s8bba98ff_4cbb_40b8_beee_296c916a23ed].[[
oracle.webcenter.upgrade.framework.exception.UpgradeException: Upgrade phase failed for RESOURCE_CATALOG:defaultScope, GenericSiteResource Id: <Resource-Catalog-Id> in scope Scope[name=defaultScope, guid=s8bba98ff_4cbb_40b8_beee_296c916a23ed].
      at oracle.webcenter.upgrade.internal.framework.DefaultUpgradeHandlerContext.reportUpgradePhaseFailure(DefaultUpgradeHandlerContext.java:224)
      at oracle.portal.core.migration.impl.ResourceCatalogUpgradeHandlerImpl.reportUpgradeStatus(ResourceCatalogUpgradeHandlerImpl.java:105)
      ...

Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.7.v20190604-418f1a1c56): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (PORTAL_WEBCENTER.IX_UNIQUE_PORTA_NAMESPACE_NAME) violated

Error Code: 1
Call: INSERT INTO WC_PORTAL_ENTITY (ID, AUX_DATE_1, AUX_DATE_10, AUX_DATE_2, AUX_DATE_3, AUX_DATE_4, AUX_DATE_5, AUX_DATE_6, AUX_DATE_7, AUX_DATE_8, AUX_DATE_9, AUX_INDEXED_NUMBER_1, AUX_INDEXED_NUMBER_2, AUX_INDEXED_STRING_1, AUX_INDEXED_STRING_2, AUX_INDEXED_STRING_3, AUX_INDEXED_STRING_4, AUX_INDEXED_STRING_5, AUX_NUMBER_1, AUX_NUMBER_10, AUX_NUMBER_11, AUX_NUMBER_12, AUX_NUMBER_13, AUX_NUMBER_14, AUX_NUMBER_15, AUX_NUMBER_2, AUX_NUMBER_3, AUX_NUMBER_4, AUX_NUMBER_5, AUX_NUMBER_6, AUX_NUMBER_7, AUX_NUMBER_8, AUX_NUMBER_9, AUX_STRING_1, AUX_STRING_10, AUX_STRING_11, AUX_STRING_12, AUX_STRING_13, AUX_STRING_14, AUX_STRING_15, AUX_STRING_16, AUX_STRING_17, AUX_STRING_18, AUX_STRING_19, AUX_STRING_2, AUX_STRING_20, AUX_STRING_21, AUX_STRING_22, AUX_STRING_23, AUX_STRING_24, AUX_STRING_25, AUX_STRING_26, AUX_STRING_27, AUX_STRING_28, AUX_STRING_29, AUX_STRING_3, AUX_STRING_30, AUX_STRING_31, AUX_STRING_32, AUX_STRING_33, AUX_STRING_34, AUX_STRING_35, AUX_STRING_4, AUX_STRING_5, AUX_STRING_6, AUX_STRING_7, AUX_STRING_8, AUX_STRING_9, CREATED, CREATOR, DESCRIPTION, DOCUMENT_REF, IS_INITIALIZED, IS_SECURED, IS_SEEDED, MODIFIED, MODIFIER, NAME, NAMESPACE, SECURITY_ID, SHORT_ID, TYPE, VERSION, VERSION_ID, PORTAL_ID, SECURITY_ENTITY_ID) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
      bind => [86 parameters bound]
Query: InsertObjectQuery(null [namespace=pageStyle/pageStyleName/pageView, id=<PageStyle-Id>, type=oracle.webcenter.portal.persistence.PageViewResource, version=1])
      at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:879)
      at org.eclipse.persistence.internal.jpa.QueryImpl.performPreQueryFlush(QueryImpl.java:972)
      at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:207)
      ...