Those days, when trying to apply Database Patches using the Oracle Enterprise Manager 12c, I was getting an error: Prereq "checkActiveFilesAndExecutables" is not executed. Invoking prereq "checkactivefilesandexecutables" Prereq "checkActiveFilesAndExecutables" is not executed. The details are: No patch location specified. OPatch failed with error code 2 ERROR: Failed to invoke 'opatch prereq checkActiveFilesAndExecutables' ERROR: Some processes …