Make sure you have in text_translated.lua file:
local t = {} (first line in the script, excluding comments
return t (last line in the script)
Hello Loisky! Many thanks for your help. I checked my lua file and these both things were already in. I found the solution of my problem. Actually it is all about syntax. I was missing the " character in one line, so the game stopped working.
After I added this missing character, everything finally worked. Anyway, thanks a lot for your help!