You click "Enable Visual Builder" and the purple spinner turns forever, or a box says "Divi Builder Timeout" and suggests steps that change nothing, or the builder opens but every save ends in "Your save has failed". Visitors still see the site; only the editor is stuck. The Visual Builder runs in your browser and talks to your own site through background requests, so when one of them is cut off (PHP limits, another plugin, a speed setting, the host's firewall) the builder waits or gives up. Two checks tell you which one it is. Below is a rebuilt example (not a real client), the two checks, and the fix for each cause.
In the dashboard go to Divi > Support Center, scroll to Divi Safe Mode and switch it on, then open the page in the Visual Builder again. Safe Mode turns off other plugins, the child theme and custom code for your login only; visitors see the normal site. The same page lists your server's PHP limits with a green or red mark next to each, which you will need below.
Switch Safe Mode off again when you are done.
On a computer, open the stuck builder, press F12 (or right-click and choose Inspect), open the Network tab and reload. Type admin-ajax in the filter box and read the Status column. If it fails on save, press Save with the tab open and read the row that appears. Then look at the Console tab and read the first red line.
| What you see | Cause | Fix |
|---|---|---|
Red marks in Divi > Support Center next to memory_limit, max_execution_time or max_input_vars; admin-ajax.php status 500 or a long wait then "Divi Builder Timeout" | The server stops the builder before it finishes: too little memory, too little time, or too few input fields allowed for a long page | Divi's own recommended values are shown next to each red mark (memory 128 MB or more, execution time 120 seconds, input vars 3000 or more). Memory can go in wp-config.php: define('WP_MEMORY_LIMIT', '256M'); above "That's all, stop editing". The other two are PHP settings: most hosts have a "PHP options" or "MultiPHP INI" screen, otherwise ask them. More in "Allowed memory size exhausted" and "Maximum execution time exceeded" |
| Builder loads, but saving a long page fails, or modules at the bottom vanish after a save | max_input_vars is too low: PHP drops the end of the page silently | Raise max_input_vars to 3000 or more (5000 for very long pages) in the host's PHP settings, then save again. The Support Center mark turns green when it took effect |
Status 403 on admin-ajax.php when you save, or a host or Cloudflare page saying the request was blocked | A firewall rule (ModSecurity, Wordfence, Cloudflare's WAF) read the page's code as an attack. This is the most common cause of "Your save has failed" | Ask the host to check the firewall log for your IP at that minute and allow that rule for /wp-admin/admin-ajax.php; in Wordfence use "Allowlist" on the blocked request under Firewall. Do not switch the whole firewall off. See also 403 Forbidden |
| Builder opens in Safe Mode, hangs without it | A plugin, the child theme or custom code (Theme Options > Integration, or a code module) breaks the builder's scripts | Deactivate plugins in halves until the builder opens; the last half you switched off holds the culprit. Speed plugins and old Divi add-on packs are the usual suspects. If no plugin is to blame, switch to the parent Divi theme for a minute, then empty the code boxes under Divi > Theme Options > Integration one at a time (copy them somewhere first). More in a plugin broke the site |
Console shows errors from files named like rocket-loader, autoptimize or wp-rocket, or about jQuery | A speed setting delays or combines scripts, including the builder's own | Turn off Cloudflare's Rocket Loader (Speed > Optimization) and exclude logged-in users from JavaScript delay and combine in your speed plugin. If you turned on Defer jQuery under Divi > Theme Options > Performance, switch it off and test again |
| Builder opens but styles are missing or show the old version; the live page looks different from the builder | Divi's generated CSS files and a cache are serving stale copies | Divi > Theme Options > Builder > Advanced > Static CSS File Generation: press Clear. Then empty your cache plugin, the host's cache and Cloudflare's. More in changes not showing on the live site |
| Nothing red anywhere, but it only fails in your usual browser | A browser extension (ad and script blockers most often) stops the builder's files | Open the builder in a private window. If it works there, turn your extensions off one by one |
Open two or three pages in the Visual Builder, including the longest one, change a word, save, and reload the public page to see it. Go back to Divi > Support Center: every PHP line should now be green. If you changed a firewall or speed setting, open the public site on your phone too, to be sure visitors still get the fast version.
max_input_vars: each save can drop more of the page. Fix the limit first, then restore the page from Divi's revision history (Ctrl+Z history in the builder, or the WordPress revisions of the page).Most of these take ten minutes once you know which one it is. If you would rather someone else finds and fixes it, that is what the box below is for. Related: Elementor stuck on the loading screen, "Allowed memory size exhausted" and changes not showing on the live site.