Solution : https://service.sap.com/sap/support/notes/843356 (SAP Service marketplace login required)
Key words :
update icnv31l set dblength2 = concat, symptom upgrade job_rsswincv fails, choose 'extras'->'force conversion', elg 1eeda635 field, 40 downward compatible kernel, call transaction se14, call transaction se37, input parameter 'stmt', changed definition 1eeda635, choose 'table'->'reconstruct'
Related Notes :
| 750096 | DB2-z/OS: 6.40 downward compatible kernel |
| 661252 | DB2-z/OS: Additions upgrade to Basis 6.40 |