Check the proposed task list alternative & & &

What causes this issue?

The task list alternative (<DS:GLOS.task_list_group>task list group</>,
<DS:GLOS.group_counter>group counter</>, and, in the case of production
versions, <DS:GLOS.task_list_type>task list type</>) has been proposed
in part by the system.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check the default values.

Error message extract from SAP system. Copyright SAP SE.