The page appears as plain text.
WHAT IT MEANS
The CSS is not loading.
THE COMMON CAUSES
A mixed content block, where CSS is requested over HTTP on an HTTPS page Incorrect site address settings after a migration A caching or minification plugin producing a broken file A missing or renamed file Permissions preventing the file being read
WHAT TO CHECK FIRST
Browser developer tools, which report which resource failed and why.
FOR MIXED CONTENT
Update hardcoded HTTP addresses to HTTPS.
For WordPress, a serialisation-aware search and replace across the database.
FOR SITE ADDRESS SETTINGS
After migrating, the stored site address may point at the old domain.
FOR A MINIFICATION PLUGIN
Disable minification and test.
It frequently breaks styling after an update.
FOR PERMISSIONS
Files must be readable by the server.
WHAT TO DO AFTER FIXING
Clear every cache.