Solution : https://service.sap.com/sap/support/notes/998575 (SAP Service marketplace login required)
Key words :
cnv type group, deletes existing data, cnv_tabname type exists, upgrade / unicode conversion, cnv_tabname data element, data element, unicode conversion, terms cnv_tabname, scheduled jobs, transaction sumg
Related Notes :
| 638258 | SLO: Deleting conversion workbench objects |