Page builder not working nor saving

I checked this at my end and found out it to be working fine at my test setup. Please try creating some new pages and then check. Please confirm if the issue  is coming on some specific page or all over the space. If it is on specific page then please share the page builder export code with us to check this. If the issue is coming all over the website then it means that there is some js error on your page. You can check the js error by using this tip: https://codex.wordpress.org/Using_Your_Browser_to_Diagnose_JavaScript_Errors Share the screenshot of the error to check. Or share the credentials with us in a private reply to check this at your website.

Well I checked your site and was able to replicate the issue . During debugging i found that the wordpress simple heartbeat call to save revisions is also returning an 500 error . refer : http://prntscr.com/cmxeuz And I also found out that you php version is also old .It is 5.3 right now . Can you please contact your webhost and upgrade the php version to  5.6 . Please also share your server php error log here to check the issue further .(upload it somewhere online and share its link here ) . error log is log file which maybe in the root of the site . (in your case it maybe in wordpress folder .) Contact webhost to find it .