Lesson 'Mathematics' for group '5A' has no available time periods.

Last updated: Mar 23, 2026

At a glance

This lesson has no valid time slots it can be placed in.

What causes this error

Every lesson needs a set of time periods in which it can be scheduled. This error occurs when the combination of teacher unavailability, group restrictions, and lesson-specific blocked periods results in zero available slots.

How to fix it

Review the following for the affected lesson:

  1. Teacher unavailable periods — Check if the teacher is marked as unavailable during all possible slots for this group.
  2. Group time range — Verify the group's MIN_TIMESLOT and MAX_TIMESLOT rules leave at least some free periods.
  3. Lesson unavailable periods — Check if too many periods have been blocked directly on this lesson.
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