Custom schedules with attached files are no longer executed

Custom schedules with attached files are no longer executed

Three days ago the custom schedules which are meant to send attached exported views in XLS format were no longer executed. In my account at  https://creator.zoho.com/ showScheduleUsageLog.do in last 3 days there is shown that the schedules failed and the reason is... Error occured please contact application owner

I meet the same situation in other 2 accounts belonging to a client.

Does someone have a similar problem?

Regards,
George