Count can only be entered for period & &

What causes this issue?

A count has already been recorded for this physical inventory document
in posting period &V1& &V2&. All further counts relating to this
physical inventory document must be performed in the same posting
period.

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?

Change the count date so that it lies within the posting period &V1&
&V2&.

Error message extract from SAP system. Copyright SAP SE.