You cannot resolve &1 &2

What causes this issue?

The checklist reference &V2& cannot be resolved.

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 whether the status for the referring checklist template allows
resolution. The checklist template must have the status 'released' and
cannot be locked.
Furthermore, the status of the project definition or phase cannot forbid
the resolution of the checklist reference.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.