Cornerstone preview could not load and the footer does'nt appear

After uploading to WP to the latest version.

My cornerstone it appears the following error:

“The preview could not load. This is most often related to a plugin conflict or aggressive page cacheing. Checking the developer console for errors could indicate what went wrong.”

I’ve traied:

deactivating all plugins
increasing site memory to 512M
clearing the cache 

Then, the footer does’nt appear in the web,

Please help.

I have the same issue. Everything just worked fine and than all of a sudden the preview doesn’t work. I’ve tried deactuvating plugins, clear cache, disable cache CDN,increased the memory.

Nothing works…