502 Bad Gateway

Hello Andrew,

Thank you for your messsage.
Can you, please, send me the site info at support@web357.com, by copying and paste here the site info as you can see in this screenshot? https://make.wordpress.org/core/files/2019/04/site-health-info-1024×551.png

Hmm it seems that your ngnix server blocks the plugin.
I suppose that your hosting provider should increase some values in the conf file.

https://stackoverflow.com/questions/23844761/upstream-sent-too-big-header-while-reading-response-header-from-upstream
fastcgi_buffers 16 16k;
fastcgi_buffer_size 32k;

Thanks.​

Yiannis Christodoulou