Error in syntax check &1

What causes this issue?

The syntax check found errors in your entry.

System Response

The cursor marks the place where the error occurs.

How to fix this error?

Check your entry and correct the expression where the error occurs.
You can still save the source code for the dependency if the syntax is
incorrect. However, you cannot then use the dependency for
configuration.

Error message extract from SAP system. Copyright SAP SE.