No fiscal year defined for the analysis period

What causes this issue?

You have not maintained any fiscal years for the analysis period &v1&
to &v2& in the current fiscal year variant &v3&.
To execute consistency checks, the system requires information
regarding the fiscal years. Certain fields must be unique for each
fiscal year.

System Response

The system issues a warning, which you can ignore by choosing "ENTER".
ACHTUNG:
If you later maintain fiscal years for the affected time period, no
consistency checks are made by the system. You should only skip the
warning if the time periods involved are far in the future.

How to fix this error?

Ignore the warning to confirm the intended entries.
Choose Cancel if the planned entries are likely to lead to
inconsistencies.
If required, first maintain the fiscal year variant for the affected
time period.

Error message extract from SAP system. Copyright SAP SE.