You must use these files:
C510_R1FA035_MAIN_GENERIC_KT_RED53
C510_R1FA035_FS_APAC-ANZ_RED53
K850i_1201-0102_R11A_GENERIC_APAC-ANZ (K850 custpack is same with C510 custpack)
After flashing update via SEUS.
OR
With A2uploader click File System Tool and drag & drop: customize_upgrade.xml to TPA > PRESET > CUSTOM
Download: C510 customize_upgrade APAC-ANZ.rar
Then turn on phone and when you see "Please wait" ... again turn off and update via SEUS.




