Asset class & does not exist (Enter another reference class)

What causes this issue?

You have chosen asset class &V1& as a reference class. Asset class
&V1& does not exist.

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?

Enter another class as a reference class.
Using the F4 function, you can use a matchcode to help you search for
a suitable asset class to use.

Error message extract from SAP system. Copyright SAP SE.