How To Fix W8060 - Table action "Append" is only possible for single-level expressions

SAP Error Message - Details

• Message type: E = Error

• Message class: W8 - Workflow: Expressions, data flow

• Message number: 060

• Message text: Table action "Append" is only possible for single-level expressions

What causes this issue?

The table action "Append" (Syntax '//') is only possible, if the
assignment is to a single-level expression.

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?

Error message extract from SAP system. Copyright SAP SE.