you can try to finalize operation with FAR MANAGER with SEFP plugin.
Try this:
1st extract all files from the custompack with winrar/winzip etc
2nd open far manager, press alt+f1 and select SEFP. choose DCU60 , the highest speed and then choose as a boot script: db2020_52
the program will say to connect the phone. Press C on the phone keypad and plug in the cable. Then in FAR MANAGER select FS
3rd navigate in left to tpa\preset\custom
4th navigate in right where you extracted all the files from the custompack, select all and then press f5 (copy) and then hit copy.
5th after all the files are copied into the phone navigate with .. in the left side. a popup should come (" are you sure?"). select yes
6th disconect the phone, pull out the battery and then reinsert it. power on the phone. it should work now.

DISCLAIMER: I'm not responsible to any damage to the phone.