No &1 available, - may be not yet all used objects loaded.

What causes this issue?

You tried to assign an object of type '&V1&' from the used objects list.

System Response

The used objects list does not contain global data objects of the
specified type '&V1&'.

How to fix this error?

From the context menu choose "Select Existing Type" or expand all nodes
to get all used objects loaded.

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.