[TYPO3-english] EN - WIN - Calculated absolute path to typo3/sysext directory does not exist

[Thomas Crenn]

Hi,
I have this message when i click on a page in the backend :

Calculated absolute path to typo3/sysext directory does not exist.

Something in the main file, folder and link structure is wrong and must be fixed! A typical document root contains a couple of symbolic links:
* A symlink "typo3_src" pointing to the TYPO3 CMS core.
* A symlink "typo3" - the backend entry point - pointing to "typo3_src/typo3"
* A symlink "index.php" - the frontend entry point - points to "typo3_src/index.php"

My site is in local on a windows 7 distribution and i use typo3 7.6
My symlinks are, i think, perfectly fine, here is a result of a 'dir' in the root directory of my site :
06/01/2017  10:23    <REP>          .
06/01/2017  10:23    <REP>          ..
03/01/2017  12:24            13 374 .htaccess
06/01/2017  10:13    <REP>          fileadmin
04/01/2017  16:34             1 201 index.php
06/01/2017  10:23    <SYMLINKD>     typo3 [C:\wamp64\www\typo3_7.6\typo3_src\typo3]
06/01/2017  10:13    <REP>          typo3conf
06/01/2017  10:13    <REP>          typo3temp
06/01/2017  09:52    <SYMLINKD>     typo3_src [C:\wamp64\www\typo3_src-7.6.15]
06/01/2017  10:13    <REP>          uploads

I don't understand
Thanks