Fix “Unable to save temporary file for atomic writing” in Wordfence

Short version

The Wordfence firewall is trying to write to disk and failing.

Atomic writing means it writes to a temporary file first, then renames it. This prevents half written configs. If it cannot create or write that temporary file, you see this fatal error and your site can go down.

Almost always the cause is one of these:

• Wrong permissions or owner on wp-content/wflogs or its parent folder.
• Disk full or hosting quota exceeded.
• Corrupted or stale wflogs after a migration or restore.
• A strict server rule such as open_basedir or security software blocking writes there.

We will first get your site back up. Then we fix wflogs and permissions. Finally we look at long term options like using the MySQL storage engine instead of files.

---

Quick path. Pick your situation

• Your site is down with a fatal error and you cannot log in. Go to Step 0. Recover access quickly.
• You can log in to wp admin but see Wordfence errors. Start at Step 1. What this error means.
• You know the server is low on disk space. Jump to Step 3. Check disk space and quotas.

If you are not sure, just follow each step in order.

---

Step 0. Recover access if your site is down

If this fatal error is on screen and you cannot reach WordPress admin, disable Wordfence temporarily so your site can load.

Option A. Rename the Wordfence plugin folder

Use FTP or your hosting file manager:

1. Go to wp-content/plugins/.
2. Find the wordfence folder.
3. Rename it to something like wordfence-disabled.
4. Reload your site and the admin login page.

WordPress will stop loading Wordfence. The fatal error should disappear.

Option B. Rename the wflogs folder only

If you prefer to keep Wordfence active while you test:

1. Go to wp-content/.
2. Find the wflogs folder.
3. Rename it to wflogs-old.
4. If you can, create a new empty folder called wflogs.
5. Set its permissions to 755.

Wordfence will try to repopulate the folder with new files when it runs again.

Once you have access to wp admin, you can continue with the steps below and later rename the plugin folder back to wordfence and reactivate it.

---

Step 1. What this Wordfence error means

The core part is:

Fatal error: Uncaught wfWAFStorageFileException:
Unable to save temporary file for atomic writing.

Wordfence stores firewall config and logs on disk in:

wp-content/wflogs/

When it updates those files, it writes to a temporary file first. If it cannot create or update that temporary file, it throws this exception.

Common reasons:

• The web server user does not have permission to write in wflogs.
• The files or folder are owned by another user such as root.
• The disk or account quota is full so writes fail.
• A restore or migration left wflogs in a broken state.

The good news. You can usually fix this without losing your site or firewall settings.

---

Step 2. Reset the wflogs folder

Wordfence support often recommends deleting or renaming wflogs and letting the plugin recreate it.

Safely reset wflogs

1. Connect via FTP or your host file manager.
2. Go to wp-content/.
3. Download the wflogs folder as a backup if you wish.
4. Delete the contents of wflogs or rename the whole folder to wflogs-old.
5. Create a new wflogs folder under wp-content.
6. Set its permissions to 755.

Then:

1. Log back in to wp admin.
2. Go to Wordfence → Tools → Diagnostics → Filesystem and confirm there are no write errors on wflogs.
3. Visit Wordfence → Firewall. If you see prompts to rebuild firewall data, follow them.

If the error does not return, the problem was likely a corrupt or partially written config file.

If the error returns quickly, continue with permissions and disk checks.

---

Step 2b. Fix permissions and ownership

Wordfence needs to write to:

• wp-content/wflogs
• Its own plugin folder wp-content/plugins/wordfence in some cases

Typical safe defaults that Wordfence and many hosts recommend:

Directories: 755
Files:       644

The owner should be the same user your web server runs as. On many Linux hosts that is www-data, apache, or nginx.

Check and fix with your host or SSH

If you have SSH and are comfortable using it, from your site root:

cd /path/to/your/site
cd wp-content
chown -R www-data:www-data wflogs
find wflogs -type d -exec chmod 755 {} \;
find wflogs -type f -exec chmod 644 {} \;

Replace www-data:www-data with the correct user and group for your server.

If you are not sure, open a support ticket to your host and include something like:

Wordfence is showing:
"Fatal error: Uncaught wfWAFStorageFileException: Unable to save temporary file for atomic writing."

Can you please ensure that:
1) The wp-content/wflogs folder exists.
2) It is owned by the web server user.
3) It is writable by the web server user with directory permissions 755 and file permissions 644.

Once your host confirms the folder is writable, retest.

---

Step 3. Check disk space and quotas

Sometimes the error is not permissions at all. It is simply that the disk or quota is full.

Signs include messages like:

Disk quota exceeded
No space left on device

in your logs.

Check usage in your hosting panel

Most control panels show total disk usage and individual account quotas.

Look for:

• Disk usage near 100 percent.
• Inode or file count at its limit.

If you are near or over limits:

• Delete old backups left on the server.
• Remove unused themes and plugins.
• Clear large cache directories.
• Ask your host to increase disk or upgrade your plan if needed.

After freeing space, repeat the wflogs reset step and test again.

---

Step 4. Check server rules such as open_basedir or security tools

On some hosts, strict PHP path rules or panels like aaPanel or custom security tools can block Wordfence from writing to its own folders.

Examples include:

• open_basedir restrictions that do not include wp-content or the wflogs path.
• Security options labeled things like Anti XSS or base directory limit that prevent writes.
• File ownership flips where system tools create files as root instead of the web user during migrations.

If you suspect this:

1. Ask your host or panel support which path restrictions are active.
2. Ask them to confirm that wp-content and wp-content/wflogs are allowed for PHP writes.
3. If files in wp-content or wflogs are owned by root, ask them to adjust ownership to the web user.

You can mention that Wordfence needs to write firewall config and logs to wp-content/wflogs and that atomic writing is failing there.

---

Step 5. Re run WAF optimization if paths changed

If this started right after:

• Moving the site to a different server or folder.
• Changing PHP versions or handler.

then the Wordfence WAF bootstrap file wordfence-waf.php may still point to old paths.

Once permissions and wflogs are fixed:

1. In wp admin go to Wordfence → Firewall.
2. Click Manage Firewall.
3. If you see an Optimize the Wordfence Firewall button, run the wizard.
4. If you see Remove Extended Protection instead, remove it, then run the optimization again.

This will rebuild the WAF config and update its paths. It also checks that wflogs is in the right place and writable.

---

Step 6. Optional. Use MySQL storage instead of file storage

If your hosting environment is unusual or file permissions are hard to control, Wordfence can store firewall data in the database instead of files.

Wordfence calls this the MySQLi storage engine.

You can read about it in their docs, but in short:

• It moves WAF storage from wp-content/wflogs into a table in your database.
• It can avoid issues with shared hosting file permissions.

Switching storage engines is more advanced and should be done carefully. If you are not comfortable editing wp-config.php and Wordfence constants, ask your developer or host to help and follow the official Wordfence guide.

---

Step 7. What to send to your host or Wordfence support

If this error keeps coming back, gather a bit of information before you reach out.

Include:

• The exact error text:Fatal error: Uncaught wfWAFStorageFileException: Unable to save temporary file for atomic writing.
• Your WordPress version and Wordfence version.
• A note on whether deleting or recreating wp-content/wflogs helped and for how long.
• Current permissions and owner for:
  • wp-content/
  • wp-content/wflogs
  • wp-content/plugins/wordfence
• Any disk quota or “no space left on device” messages from your host.

Send this to:

• Your hosting support first if you suspect disk, ownership, or server rules.
• Wordfence support if permissions and disk are clean but the error persists.

This gives them what they need to spot file system problems quickly.

---

Verification checklist

You are in good shape when:

• Your site loads without the Wordfence fatal error.
• Wordfence → Tools → Diagnostics → Filesystem shows no write errors on wflogs.
• Wordfence → Firewall does not show storage or rules update warnings.
• The wflogs folder contains fresh files and is not growing out of control.

---

Still stuck?

For AI help

Hit Continue Chat below and tell me:

• Whether you can access wp admin now.
• What you see in Wordfence → Tools → Diagnostics → Filesystem.
• The permissions and owner for wp-content/wflogs.
• Any “disk full” or quota messages from your host.

I can help you turn that into a precise set of instructions for your host or developer.

For expert human help

Scroll down to the contact form below. Enter your name, email, and WordPress needs. Atiba will get back to you as soon as possible.