How To Fix WL492 - Comparación no evaluable ya que elemento/expresión '&' no definidos.

SAP Error Message - Details

• Message type: E = Error

• Message class: WL - Workflow: run-time messages

• Message number: 492

• Message text: Comparación no evaluable ya que elemento/expresión '&' no definidos.

¿Cómo arreglar este error?

Make sure that the workflow/work item variables involved or object
attributes are assigned a value. Variables can be assigned values
from the result parameters of a work item (by binding)
by an assignment (container operation)
by pre-assignment (initial values) at the start of the workflow/work
item.
If the variables involved still do not contain any data, there may be
an error in the definition or when carrying out the binding.

Extracto de mensaje de error del sistema SAP. Copyright SAP SE.