To remove a mass from the scheduling process, make the mass inactive. Inactive masses are still visible within the program and can optionally be included on reports, but they are ignored by the scheduling process.
You can select a permanent mass in the Replaces field of a special mass. This prevents the permanent mass from being scheduled during the week the special mass occurs.
Let's say the church secretary added a Special Sunrise Easter Mass at 6:30 AM that conflicts with the normal Sunday morning 7:00 AM Mass. On Easter Sunday, she cancels the 7:00 AM Mass.
In the above example, do not delete the 7:00 AM mass to prevent it from being scheduled on Easter Sunday with the intention of entering it again the following week.
If you delete a mass, you break the association between the minister preferences and the now non-existent mass, so the preferences in all the ministers' records are deleted. Entering a new mass the following week does not restore the preferences.