Annotation '&1: &2' must not be used here.

What causes this issue?

The annotation <(>&<)>1 with the value <(>&<)>2 is used in a
non-analytical CDS view, which is not supported.

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?

Either remove the annotation or use a valid annotation value.

Procedure for System Administrators

Contact the corresponding developer of the CDS view to correct the
error.

Error message extract from SAP system. Copyright SAP SE.