Can't save a campaign

I’ve trouble when I try to save a campaign. When I open the campaign generator, the button ‘Apply’ or ‘Close the generator’ seems to be disabled. When I click on this, nothing appends.
(when I execute Mautic.closeCampaignBuilder() in the console of Chrome, the campaign is saved)

My configuration :
Mautic v2.11.0
PHP : 7.1.13
Server API : FPM/FastCGI

Best regards,

Marc JARROSSAY

Yes, I’m facing the same problem, and I’m using Cloudflare (SSL Flexible). You you have and advices?
Thanks