Issue installing screenCustomization_V5.0 plugin on Projeqtor V6.4.3

Hello
Once V6.4.3 installed, I realised the screenCustomization plugin needed to be upgraded. But I still have errors.
- Should I delete the ...\plugin\screenCustomization\ before installing the new version ?
- Even after upgrading rights (777) on folders and files, I still have the following error message:

2017-10-31 10:03:37.320 ===== TRACE ===== New plugin found : screenCustomization_V5.0.zip
2017-10-31 10:03:37.331 ===== TRACE ===== Plugin unzipped succefully
2017-10-31 10:03:37.335 ===== TRACE ===== Plugin descriptor information :
2017-10-31 10:03:37.335 ===== TRACE ===== => name : screenCustomization
2017-10-31 10:03:37.335 ===== TRACE ===== => description : Customization of screens
2017-10-31 10:03:37.335 ===== TRACE ===== => version : 5.0
2017-10-31 10:03:37.335 ===== TRACE ===== => compatibility : V6.4.2
2017-10-31 10:03:38.004 ***** ERROR ***** [V6.4.3] ERROR *****
2017-10-31 10:03:38.004 ***** ERROR ***** [V6.4.3] on file '/DATA/projeqtor/tool/file.php' at line (49)
2017-10-31 10:03:38.004 ***** ERROR ***** [V6.4.3] cause = unlink(../plugin/screenCustomization_V5.0.zip): Operation not permitted
2017-10-31 10:03:53.666 ===== TRACE ===== New plugin found : screenCustomization_V5.0.zip
2017-10-31 10:03:53.679 ===== TRACE ===== Plugin unzipped succefully
2017-10-31 10:03:53.684 ===== TRACE ===== Plugin descriptor information :
2017-10-31 10:03:53.684 ===== TRACE ===== => name : screenCustomization
2017-10-31 10:03:53.684 ===== TRACE ===== => description : Customization of screens
2017-10-31 10:03:53.684 ===== TRACE ===== => version : 5.0
2017-10-31 10:03:53.684 ===== TRACE ===== => compatibility : V6.4.2
2017-10-31 10:03:54.367 ***** ERROR ***** [V6.4.3] ERROR *****
2017-10-31 10:03:54.367 ***** ERROR ***** [V6.4.3] on file '/DATA/projeqtor/tool/file.php' at line (49)
2017-10-31 10:03:54.367 ***** ERROR ***** [V6.4.3] cause = unlink(../plugin/screenCustomization_V5.0.zip): Operation not permitted
2017-10-31 10:04:17.729 ===== TRACE ===== === SCREEN CUSTOMIZATION ISSUE =====================================
2017-10-31 10:04:17.729 ===== TRACE ===== Some screen customizations are not consistant any more with current version :
2017-10-31 10:04:17.729 ===== TRACE ===== - Project
2017-10-31 10:04:17.736 ***** ERROR ***** [V6.4.3] ERROR *****
2017-10-31 10:04:17.736 ***** ERROR ***** [V6.4.3] on file '/DATA/projeqtor/plugin/screenCustomization/screenCustomizationSaveField.php' at line (293)
2017-10-31 10:04:17.736 ***** ERROR ***** [V6.4.3] cause = touch(): Utime failed: Permission denied
2017-10-31 10:16:06.566 ===== TRACE ===== New plugin found : screenCustomization_V5.0.zip
2017-10-31 10:16:06.568 ***** ERROR ***** [V6.4.3] ERROR *****
2017-10-31 10:16:06.568 ***** ERROR ***** [V6.4.3] on file '/DATA/projeqtor/model/Plugin.php' at line (79)
2017-10-31 10:16:06.568 ***** ERROR ***** [V6.4.3] cause = ZipArchive::extractTo(../plugin/screenCustomization/docs/screenCustomization.pdf): failed to open stream: Permission denied
2017-10-31 10:16:06.569 ***** ERROR ***** [V6.4.3] Plugin::load() : Impossible de décompresser le fichier /plugin/screenCustomization_V5.0.zip.
Vérifiez que l'utilisateur lançant PHP a des droits en écriture sur ce fichier et plus globalement sur le répertoire /plugin.

It looks like the new plugin was installed, but with incompatibilites on the Project object.
More, on the plugin screen in Projeqtor, the installed plugin is still based on the previous version, and the zip file of the new version is still available on the right side (printscreen attached).
What should I do? Thanks

Already done (see file attached)