SchedulerGenericAgentTaskManager error in system log

[gsalin]

Hi,
I upgraded znuny from 6.5.18 to 6.5.23 this morning, without problem.
My colleague told me there was a missing feature...while searching for a solution, I discovered a lot of error messages in system logs
Service : OTRS-otrs.Daemon.pl - Daemon Kernel::System::Daemon::DaemonModules::SchedulerGenericAgentTaskManager-85
Message : Schedule: 0,0 3,3,5,5 * * 7,7 is invalid.

but I'm not able to guess where the problem comes from...I checked the generic agent jobs...but found no clue, as well as in the database

Do you have an idea where to search?

thank you for your help
Gérald