Solution : https://service.sap.com/sap/support/notes/707114 (SAP Service marketplace login required)
Key words :
admin role - content administration - portal content studio - migrated c2, empty column - choose edit - choose page 3, select 2 column layout - move hidden iview, default show layout 1 column - set, move hidden iview, set 1 column layout, add 1 column layout, symptom empty column, hidden iviews inside, mapping andskipping file
Related Notes :
| 732461 | Migration of EP & KM from 5.0 to NW '04 - Central Note |