- login to the Admin Console
- go to the Configuration → Website → Modules section
- disable all modules, except In-Portal
- go to the Tools → System Tools button
- press the Deploy button
- go to the Logs & Reports → System Log section
- confirm, that such warnings weren't added during unit config cache rebuild (happens during deployment):
* Prefix p doesn't exist when trying to hook from rel:OnDeleteForeignRelations in ...\core\kernel\managers\hook_manager.php on line 97