To transport table contents, key must be filled

What causes this issue?

You want to transport some contents of the table &V1&.
You need to specify which entries of the table you want to transport in
the key. For example, if you want to transport the entire table
contents, enter <LB>*</> in the key.
However, the key may not be empty.

System Response

The function terminates.

How to fix this error?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.