Solution : https://service.sap.com/sap/support/notes/796317 (SAP Service marketplace login required)
Key words : 
invalid stock object reason, message number /sapapo/stock013, terms /sapapo/stock013, /sapapo/om_check_activities report, /sapapo/om_check_activities program, storage location resources, source code enhancements, application log indicating, 045 inconsistent stock, application error
Related Notes : 
       
| 1065366 | /SAPAPO/OM_LC_UPGRADE_51: Problems during the upgrade | 
| 932837 | /SAPAPO/OM_LC_UPGRADE_50: Problems during upgrade | 
| 814036 | Change of storage location in R/3 work center/APO resource | 
| 770673 | /SAPAPO/OM_LC_UPGRADE_41: Problems during the upgrade | 
| 681010 | /SAPAPO/OM_LC_UPGRADE_3X_40: Problems during upgrade | 
| 603593 | Deleting from check programs |