After upgrading Identity Manager, schema update errors appear in the application server log file:
"Task Persistence database schema was not upgraded successfully."
Identity Manager 12.6 SP7
This issue could be a symptom of the database upgrading script not completing correctly.
Change directory to "C:\Program Files (x86)\CA\Identity Manager\IAM Suite\Identity Manager\tools\db\taskpersistence\"
Choose the folder with the version of your database (Oracle, MS SQL) and then run the script for upgrading from 12.5 version.
(idm_db_sqlserver_upgrade_125.sql or idm_db_oracle_upgrade_125.sql)