this problem occurs when the game is updating then you didn't unpatch the English patch.
Or you used the latest patch and you didn't unpatch your old english patch.
Try this:
Go to
DB_CT_TW/localize/TAIWAN/pack then delete this 3 files.
Then also delete this 1 file in
DB_CT_TW/pack
Now try to Install the English patch.
If it doesn't work. Just uninstall and re-install the game. then let the launcher update, then after that close the launcher. Put those 2 files (DBO english patch v2.2 & translation.txt) in
DB_CT_TW with the launcher.
Hope it helps. Good luck!