Unknown error occurred during selection with structure reader (entity &1)

What causes this issue?

The structure reader could not select the requested data because the
data base access module &V2A& ends with an exception.
The structure reader has just selected the entity &V1&.

System Response

The selection is cancelled and the result is undefined. The
functionality you started may possibly be carried out the next time you
call it up.

How to fix this error?

Call up the function again.
If the error occurs again, contact SAP.

Error message extract from SAP system. Copyright SAP SE.