I spend many hours tonight with a friend figuring out what's happening and solving my Anycubic Vyper firmware update. I had various issues :
While updating with the current version (2.4.5 as of today) I had many issues from no file update (the firmware update program display a list of file with 000 values on their right showing that nothing is processed and the checksum at the end having done nothing
Partial update leading to corrupted graphical interface freezing or blinking with locked actions/menus.
Never-ending update process blocking in "ICL" files (waited more than 40 minutes)