@Mervan could you try to specify a value for the Calendar ID. I see in your case it’s empty.

I guess since you haven’t specified any calendar, when trying to save the PM Action, this validation fails.

Additionally, you could setup a default maintenance calendar in Object Properties:

Hİ @Marcel.Ausan ,

Thanks for your answer. Unfortunately the problem persists.

@Mervan I just checked the code where this warning is triggered.

My assumption is that based on the Calendar setup at maintenance organization level, it can’t find a next working day → therefore throwing the warning.

temp_date_ := Work_Time_Counter_API.Get_Next_Work_Day__(Organization_Api.Get_Calendar_Id(newrec_.org_contract, newrec_.org_code), counter_, (trunc(nvl(newrec_.valid_from, newrec_.start_date)) - 1));
         IF temp_date_ IS NULL OR ( temp_date_ - trunc(nvl(newrec_.valid_from, newrec_.start_date)) > 7 ) THEN
            Client_SYS.Add_Warning(lu_name_, 'NOMAINTCAL: The calendar start date is later than the valid from date of the PM. Do you want to continue?');
         END IF;

Could you check the calendar setup at Maint Org level?

The solution is great.Thank you @Marcel.Ausan 

Glad I could help!