Create depreciation key "0000"

What causes this issue?

You want to assign depreciation area &v1& of this asset to a group
asset. However, there is no depreciation key in the data record of the
input file, nor could the system determine a default depreciation key
from the asset class.

System Response

The depreciation for this asset is supposed to be calculated in
depreciation area &v1& using the group asset, and the system uses the
depreciation key of the group asset for this depreciation. Therefore
any depreciation key can be transferred to the asset in this
depreciation area.
However, it is important that the asset receives a depreciation key
(any key) in depreciation area &v1&, so that the checks for the posting
transactions run correctly. The system therefore tries to enter
depreciation key "0000" in depreciation area &v1& of the asset.
Depreciation key "0000", however, is not defined in chart of
depreciation &v2&.

How to fix this error?

Chooose one of the following options:
Define depreciation key "0000" in chart of depreciation &v2&.
Enter a depreciation key as default value in asset class &v3& for chart
of depreciation &v2& in depreciation area &v1&.
Transfer a depreciation key in the data record of the input file in
depreciation area &v1&.

Error message extract from SAP system. Copyright SAP SE.