Solution : https://service.sap.com/sap/support/notes/339721 (SAP Service marketplace login required)
Key words : 
client copy/client transport, terms sapscript reason, text copying phase, complete text tables, including support packages, symptom long texts, client transport, client copy, support package, pstxb tables
Related Notes : 
       
| 601196 | Client copy: Problems with report RCTXTCPY | 
| 589886 | CC-ERROR: Performance with the remote SAPscript copying | 
| 567573 | Client transport of forms | 
| 511042 | Obsolete forms after upgrade/Support Package | 
| 338578 | CC-TOPIC: Error in client transport as of 4.5 | 
| 315837 | CC-ERROR: Texts are missing after RESTART | 
| 206523 | CC-RELEASE: Client copy errors in 4.6C and 4.6D | 
| 180541 | CC-INFO: Performance problem when copying text | 
| 96732 | CC-INFO: DB2/390 - client copy is very slow | 
| 68896 | R3trans: Performance problems and cluster | 
| 42770 | missing long texts after client copy | 
| 20497 | CC-INFO: Long texts with a client copy |