object_version_number

Dear All,

I am working with the API to update an employee but sometime I am facing a problem with the object_version_number knowing that i always create a query to select the last one.

error:

ORA-20001: The HR object is invalid

Cause:The HR object which is attempted to be locked is inconsistent with the corresponding ob

Action:Retry the action with the correct object version number.

this query gives me the last object version_number .

so why i get this error.

please advise.