Solution : https://service.sap.com/sap/support/notes/570040 (SAP Service marketplace login required)
Key words :
customer fact sheet, source code corrections, terms infoblock cl_crm_cckpt_io_lastactivities, case infoblock cl_crm_cckpt_io_lastactivities, symptom infoblock, althoughactivities exist, caused directly, solution apply, 20 activities, activities