Enter a valid template code for object &1 &2

What causes this issue?

The system checked the code to be generated by the defined configuration
or template. This check found an error. The specified element &1 &2 is
missing.

System Response

The system terminates generation of the implementation but may have
generated other objects.

How to fix this error?

Contact the author of the current configuration class.
To find the configuration class of the current configuration, choose
transaction <DS><DS:TRAN.SIW>SIW</></>. In the menu path choose <LS>Goto
-> Customizing (IMG) -></> <DS><DS:SIMG.VSIW_CONFIG>Define
Configurations</></>.

Procedure for System Administrators

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.