Solution : https://service.sap.com/sap/support/notes/807508 (SAP Service marketplace login required)
Key words :
update t005t set landx50 = space, t005t landx50 field, t005t text table, longer country names, t005 country table, landx50 field, t005t table, table t005t, country key, longer occur
Related Notes :
| 506465 | Problem with table fields (data types CURR and LANG) |
| 444054 | Country name in table T005T is too short |