At a glance

A scheduling rule references a period number that does not exist.

What causes this error

Class groups can have rules that restrict which periods lessons can be placed in (e.g. earliest start, latest end). This error occurs when the period number in the rule exceeds the total number of configured periods.

For example, if you have 8 periods (numbered 0-7) and a rule refers to period 12, the rule is invalid.

How to fix it

Go to the class configuration rules for the affected group and update the rule to a value within the valid range shown in the error.

Back