I have never done this myself so, not sure I can help out on the errors. There is another option and that is to translate everything through Studio > Polyglot. Just note that it will take a while to translate everything.
MuhammeT - It is very important to make sure you follow each step. Looking at the #1 in the tutorial it says to create your own directory /modules/ directory so, something like this:
/modules/muhamme/turkish (I wouldn't use boonex)
The next step tells you to copy all the folders from the /modules/boonex/russian/ into your own directory (above).
The proceed with the other steps. Take note to #7 where it tells you it's best to translate from English by deleting the ru.xml from your directory and replacing it with the en.xml from modules/boonex/english/data/langs/system/en.xml and then rename it to whatever format you are using such as turk.xml
Then you can translate that turk.xml (which is in English at the moment) to what you need. Good Luck!