What causes this issue?

The specifications for transaction type &V1& are that the gain/loss
from asset retirement should be posted to a profit and loss account,
as well as to an asset which is specifically set up for this purpose.
This combination is not allowed.

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 transaction type entered.

Error message extract from SAP system. Copyright SAP SE.