What causes this issue?

The legacy data transfer date and the last closed fiscal year do not go
together. The earliest possible date for the legacy data transfer is the
last day of the last closed fiscal year.
Example for the correct specification:
Legacy data transfer 12.31 current year -> last closed fiscal year:
Current year
Legacy data transfer 06.30 following year -> last closed fiscal year:
Current Year

How to fix this error?

Correct the date of the legacy data transfer &V3&.
This is not required if you simply want to display the legacy asset
data.

Error message extract from SAP system. Copyright SAP SE.