SOLVED ! This helped me with translating Gravity Forms with qTranslate plugin . All you need to od is install another small and free plugin : === qTranslate support for GravityForms === https://github.com/mweimerskirch/wordpress-qtranslate-support-for-gravityforms and it works great !
When you move a WordPress instalation from one server to another, after you have all files in place, the database, and the database meta updates for the server address you must clear the PERMALINKS . Go to Permalinks -> select some option -> re select old options -> Click save . All pages should be working now . If you still have problems, check folder permissions or user server permissions with the apache service .
So fields and strings are not translatable with your .po editing plugin . Widgets and other data strings are stored in the database, not in the php files . qTranslate let's us use in two ways, if there is no other option : <!--:en-->My English Title<!--:--><!--:fr-->My French Title<!--:--> OR a better way, but it's not always supported : [:en]My English Title[:fr]My French Title "and qTranslate does the rest :)" as the author said in the stackoverflow post were I found this great answer .
For a multi language frontend WordPress website you will need the following plugins : 1. Codestyle Locations - scan themes / plugins / files and generate translatable data fields 2. qTranslate - add a frontend options to be able to select between the languages or 2. WMPL (license cost $80 per year) Add the following line to wp-config.php for the default language (both front &back-end) : // Comment define('WPLANG', 'de_DE'); // en_EN for english, fr_FR for french and so on