I installed. it is not translated. Although i try to fix of space between the text and the ':'. I went to follow your guide i found it exist in Translated Terms. I don't know why it is.

I have seen this issue myself, caused by multiple entries of the untranslated field as source in the database. Another cause is the usage (or missing) of space between the text and the :

If you go to Settings -> Application Terms -> Translated Terms

Search for your original string you want to translate, make sure it only exists once for every language.

Did you try to install your translations on a clean database? What happened with the errormessage, is it translated?