TYPO3 Core

Everything was ok in 6.xx versions of Typo3. After upgrading Typo3 7.xx, extensions don't work in Turkish language.

Our default language is Turkish, and second language is English:

config.linkVars = L
   config.sys_language_uid = 0
   config.language = tr
   config.locale_all = tr_TR
   config.htmlTag_langKey = tr
   config.sys_language_mode=content_fallback ; 1

[globalVar=GP:L=1]
   config.sys_language_uid = 1
   config.language = en
   config.locale_all = en_EN
   config.htmlTag_langKey = en
   [global]

In this case, we can translate everything. Content elements are ok as well. But when we add an extension just like Powermail or Language Selection, the extension works only in English version of the pages. I thought the problem was caused by general Default Language issues and have been trying to solve the problem for 3-4 days. But when i changed the default language to German, French or English in TypoScript, the extensions work in default language, too. So i see the problem is related to Turkish language. I hope you can find a solution for that soon.