Help Locale Change

[AlleXuSS 345]

Hello i usually don't ask for help if i can resolve alone but in this case i ran out of controll
so i want to change the Client Locale that locale.cfg and the locale_de,en(etc) so my client is normal on "DE"language 
so i tried to change it by copying the content of the "DE" directory and replace (Locale_interface and Locale_game as RO locale)
i know if u want to change the rest of the files most important is "ui" folder even without touching that i get an invisible character after login
if i pick it no sound at all and after some seconds i get crash with apparently in syserr "PC or PC2" loading errors tried almost every posible way still dosn't want to work!
Fun FACT after 2-3 crashes after another 2tries i open client and login surprise Showing Character and i can enter on the server!
i never encountered this type of problem! .. 

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