SAP Message WL382 - Expression '&' for task: Error during evaluation or incorrect data type

Diagnosis
Expression '&V1&' should return a task for Workflow step no. &V4&.However, the result does not have the correct data type or returnserrors during the evaluation:
Expression:,,'&V1&'
Value:,,,,'&V2&'
ABAP type:,,'&V3&'

System Response
The Workflow was stopped and given an error status.

Procedure
Please correct the definition or implementation of the expression toreturn a value with reference to the DDIC domain HROBJEC_14 (ABAP type:C14) liefert. You should note that numbers alone may not be usedbecause they must be preceded by an org. object type "T ...", "WF...",etc.
Multi-line elements and object references are also not possible at thispoint.
A workflow which has been stopped can be continued by selecting thefunction Restart after error.