Solution : https://service.sap.com/sap/support/notes/568526 (SAP Service marketplace login required)
Key words :
function code 'doc_mat_link' reason, function code 'doc_mat_link', respective cad system, implement badi 'cdesk_badi_main', function code, badi cdesk_badi_main, cad-desktop, cad desktop, system transfers, object link