2386912 - DVD listed in upgrade phase PREP_INPUT_CHECK/READDATA_EXP in SUM cannot be found in SAP Support Portal

Netweaver 7.5 based system is set as upgrade target.  System upgrade  process runs into error in phase PREP_INPUT_CHECK/READDATA_EXP in SUM(>= SP18).  A list of suitable DVDs are listed in SUM screen, but some of them cannot be found in SAP support portal, as shown in the screenshot below.

System upgrade with target system based on SAP Netweaver 750, SUM >=SP18

PREP_INPUT_CHECK/READDATA_EXP, PREP_INPUT_CHECK, READDATA_EXP, DVD,  51040868_1, 51040868_2, 51040868_3, 51040868_4, 51040868_7, 51040868_8, 51040868_9, 51040868_10, 51040868_11, 51040868_12, 51040869_1, 51040869_2, 51040869_3, 51040869_4, 51040869_5, 51040869_6, 51040869_7, 51040869_8, 51040869_9, 51040869_10, 51040870_1, 51040870_2, 51040870_3, 51040870_4, 51040870_5, 51040870_6, 51040870_7, 51040870_8, 51039400, 51040119, 51042611_1, 51042611_2, 51042611_7, 51042611_8, 51042611_9, 51042611_10, 51042611_11, 51042611_12, 51042612_1, 51042612_2, 51042613_5, 51042613_6, 51042613_7, 51042613_8, 51042613_9, 51042613_10, 51042615_1, 51042615_2, 51042615_3, 51042615_4, 51042616_1, 51042616_2, 51042616_3, 51042616_4, 51042616_5, 51042616_6, 51042616_7, 51042616_8, 51042610, 51042608, 51041985_1, 51041985_2, 51041985_3, 51041985_4, 51041985_5, 51041985_6, 51041985_7, 51041985_8, 51041986_1, 51041986_2, 51041986_3, 51041986_4, 51041986_5, 51041986_6, 51041986_7, 51041986_8, 51041987_1, 51041987_2, 51041987_3, 51041987_4, 51041987_5, 51041987_6, 51041987_7, 51041987_8, 51041988_1, 51041988_2, 51041988_3, 51041988_4, 51041988_5, 51041988_6, 51041994, 51041990, 51041531, 51041532, 51041544, 51041542, 51041536, 51041537, 51044252_3, 51044252_4, 51044252_13, 51044252_15, 51044252_20, 51044252_21, 51044252_22, 51044252_26, 51044252_27, 51044252_28, 51044252_29, 51043284, 51043284, 51042228_1, 51042228_2, 51042228_3, 51042228_4, 51042228_5, 51042234, 51042235, 51044253_3, 51044253_4, 51044253_11, 51044253_13, 51044253_17, 51044253_18, 51044253_19, 51044253_22, 51044253_23, 51044253_24, 51044253_25, 51043228, 51043228, 51044471, 51044472, 51044473, 51044474, 51044475, 51043206, 51043220, 51045124_1, 51045124_2, 51045124_5, 51045124_6, 51045124_7, 51045124_8, 51042349, 51042350, 51048078_1, 51048078_2, 51048079_1, 51048079_2, 51048081_1, 51048081_2, 51048082_1, 51048082_2, 51048083_1, 51048083_2, 51048084_1, 51048084_2, 51048085_1, 51048085_2, 51048086_1, 51048086_2, 51048087_1, 51048087_2, 51048088_1, 51048088_2, 51043624, 51046726, 51048107_1, 51048107_2, 51048107_3, 51048107_5, 51048107_6, 51048107_7, 51048107_8, 51048107_9, 51048107_10, 51047454, 51047454, 51048072, 51049324, 51050818_1, 51050818_2, 51050818_3, 51050818_4, 51050818_5, 51050818_6, 51050818_7, 51050818_8, 51050818_9, 51050818_10, 51050819, 51050819, 51048078_1, 51048078_2, 51048079_1, 51048079_2, 51048081_1, 51048081_2, 51048082_1, 51048082_2, 51048083_1, 51048083_2, 51048084_1, 51048084_2, 51048085_1, 51048085_2, 51048086_1, 51048086_2, 51048087_1, 51048087_2, 51048088_1, 51048088_2, 51046680, 51046678, 51048107_1, 51048107_2, 51048107_3, 51048107_5, 51048107_6, 51048107_7, 51048107_8, 51048107_9, 51048107_10, 51047885, 51047885, 51047885, 51047885, 51050818_1, 51050818_2, 51050818_3, 51050818_4, 51050818_5, 51050818_6, 51050818_7, 51050818_8, 51050818_9, 51050818_10, 51050882, 51050882, 51050882, 51050882, 51050882, 51050881, 51050881, 51050879, 51050879, 51050879, 51050880, 51050880, 51050826_1, 51050826_2, 51050826_3, 51050826_4, 51050826_5, 51050826_6, 51050826_7, 51050826_8, 51050826_9, 51050826_10, 51050829, 51050829, 51050829, 51050627_1, 51050627_2, 51050627_3, 51050627_4, 51050627_5, 51050627_6, 51050627_7, 51050627_8, 51050627_9, 51050627_10, 51050610, 51050610, 51050610, 51050610, 51050610, 51050610, 51050610, 51050606, 51050606, 51050606, 51050704, 51050704, 51050704, 51050580, 51050580, 51050580 , KBA , BC-UPG-PRP , Upgrade Preparation , Problem