Solution : https://service.sap.com/sap/support/notes/1294332 (SAP Service marketplace login required)
Key words :
symptom customer defined long texts, terms customer defined field reason, create data element named grpc_api_customfield_label, prerequisites program error solution, manual pre-correction, type grpc_api_customfield_label, manual steps, correction instructions, domain grpc_api_customfield_value, unlimited size
Related Notes :
1287057 | PC2.5 Support Pack 7 - Master Note |
1269306 | Customer Defined Longtexts using Subtype |