WordPress Block Editor Not Loading or Blank Screen
You open a post or page to edit it and get a blank white screen, an endless spinner, or "The editor has encountered an unexpected error." The content is usually safe — something is stopping the editor's code from running.
Common signs of this issue
- Opening a post or page in the editor shows a blank white area where the content should be.
- You see "The editor has encountered an unexpected error" with buttons such as Attempt recovery, Copy post text, and Copy error.
- The editor loads forever with a spinner, or the toolbar appears but blocks never do.
- The rest of the dashboard works fine — only editing posts or pages is broken.
- Saving fails with "Updating failed" or "The response is not a valid JSON response".
- It started after a WordPress, plugin, or theme update, or after installing a security or caching plugin.
Safe checks you can do yourself
None of these require sharing passwords with anyone.
- If you see the unexpected error screen, click Copy post text first and paste it somewhere safe. Then click Copy error and save that too — it is exactly what a developer will want. After that, try Attempt recovery.
- Open the same post in a private or incognito window, then in a different browser. If it works there, the cause is on your computer: a browser extension (ad blockers, grammar checkers, and password managers are frequent culprits) or old cached files.
- Check whether it is one post or all of them. A single broken post usually means one block or pasted content is the problem. Every post failing points to a plugin, theme, or server issue.
- Go to Tools > Site Health. If it reports that the REST API encountered an error or an unexpected result, that is a strong clue: the block editor depends on the REST API, and security plugins, firewalls, or Cloudflare rules that block it will stop the editor loading.
- Think about what changed most recently. If a plugin update happened the same day, that plugin is the first suspect. Deactivate just that one plugin and try again.
- For a safer way to test plugins, install the free Health Check & Troubleshooting plugin and use its Troubleshooting Mode. It disables plugins and switches to a default theme for your login only, so visitors see the site as normal while you test.
- Check Tools > Site Health for warnings about an outdated PHP version or low memory. A recent WordPress update on an old PHP version can leave the editor unable to load.
- If you only need to make an urgent change, you can still edit the post's text another way — ask your developer, or use the Classic Editor plugin as a temporary stopgap while the real cause is found.
What this usually means
The block editor is a large piece of JavaScript that runs in your browser and talks to your site through WordPress's REST API. If any part of that chain fails — a script conflict, a blocked API request, a browser extension rewriting the page, or a plugin error — the editor has nothing to draw, and you get a blank screen or the unexpected error message. Your post itself is stored safely in the database the whole time.
The most common causes are a plugin that adds its own blocks or editor features conflicting with a WordPress update, a security plugin or firewall blocking REST API requests, a browser extension, caching or optimisation plugins combining scripts incorrectly, or a server running a PHP version that is too old for the current plugins. Less often, a single post contains a malformed block from pasted content, which only breaks that one post.
Working out which of those it is matters because the fixes are very different. A browser extension is a two-minute fix on your own computer. A REST API block needs a change to a security setting or firewall rule. A plugin conflict may need an update or a replacement plugin. Testing in the order above usually narrows it down without changing anything visitors can see.
What not to do
- Don't keep clicking Attempt recovery repeatedly without first copying the post text and the error.
- Don't delete the post and start again. The content is almost always still in the database and in its revisions.
- Don't deactivate every plugin at once on the live site. Use Troubleshooting Mode or test one plugin at a time.
- Don't switch off your security plugin entirely to see if it helps; adjust or test its REST API settings instead.
- Don't roll back WordPress itself as a first step. A plugin or browser cause is far more likely.
- Don't paste large blocks of content from Word or other sites into the editor while it is unstable — that can create the very block errors you are trying to avoid.
When to get help
If the editor fails in every browser, Site Health shows a REST API error you can't trace, or the problem began after an update and you can't tell which plugin caused it, it is worth getting a developer to look. They can read the copied error and the browser's console in a few minutes and usually spot the conflicting script straight away. Help also makes sense if you have a deadline and need content updated now — someone can make the edit safely while fixing the underlying cause.
Not sure what to do next?
Answer a few short questions and we'll point you to the safest next step — DIY, a freelancer, or a direct review. No passwords required.
Is this a business website? If this issue may be costing you leads, sales, or trust, you may want a direct review instead of trial and error.
Frequently asked questions
What does "The editor has encountered an unexpected error" mean?
It means a script inside the block editor crashed while loading or displaying your post. It is usually caused by a plugin conflict, a browser extension, or one malformed block, not by lost content.
Is my post lost?
Almost never. The content is stored in the database and in post revisions. Use Copy post text on the error screen to keep a copy while you fix the editor.
Why does the editor work in incognito mode but not in my normal browser?
Because incognito usually runs without your extensions and without cached files. One of your browser extensions or an old cached script is interfering with the editor.
What is the REST API and why does the editor need it?
It is how the block editor loads and saves your content behind the scenes. If a security plugin, firewall, or server rule blocks it, the editor cannot load posts or save changes.
Should I install the Classic Editor plugin?
It is fine as a short-term way to keep editing, but it hides the problem rather than fixing it. Many themes and plugins now expect the block editor, so find the cause too.
Only one post fails to load. What does that mean?
Usually that the post contains a block the editor cannot read, often from pasted content or a removed plugin's block. A developer can repair the block or restore an earlier revision.