Retention Policy Service Returns A "Violation Of PRIMARY KEY constraint PK__#Orphans" (4278153)

Retention Policy Service returns an error trying to delete messages:

Violation Of PRIMARY KEY constraint 'PK__#Orphans__C87C037CCAB5937D'. Cannot insert duplicate key in object dbo.#Orphans

A duplicate key error found in the Orphans table according to the RPS.wlog:

WORKAROUND

1. Make a backup of the SQL database
2. Stop the ArchiveManager Retention Policy Service
3. Download the file "Workaround_RPS.zip" attached to this article
4. Copy and extract the file in the SQL server
5. Open SQL Management Studio, click on File->Open->File and select the script "workaround for rps.sql"
6. Run the script and wait until the script has run successfully. 
7. On SQL Management Studio, expand SQL Server Agent->Jobs, rigth-click on "CleanTempTable" job and select the option Start Job at Step. Wait until the jobs end.

         8. Start the ArchiveManager Retention Policy Service. Let the retention policy run twice and check if the error is not present