Help requested. Admin bar and footer desappeared

Of course it is surely a javascript conflict...

Since 4.1 update, no more admin bar nore footer in all sites on one network.

Deactivated ALL plugins (event network activated ones), and i am absolutely unable to understand what happens. No specific error, and this what ever the theme or the site.

Something multisite related sure :slight_frown:

How can you help ?

The network is my main one

Thanks !