Only one object can be used in this mode

What causes this issue?

This application can only copy one object from the search result.

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?

Select one object to copy.
If you want to copy more than one object from the class in Variant
Configuration, you must set the <LS>Multiple selection</> indicator in
the additional data for the class.

Error message extract from SAP system. Copyright SAP SE.