How to Fix the ‘Preview Could Not Be Loaded’ Error?
- No Theme: Some of your theme files are missing.
- Corrupted .htaccess: ‘Your site’s .htaccess file appears to be missing.
- HTTP Errors: format is < error message> content depends on the code.
Solutions. Try the following:
- Enable Safe Mode.
- If the error message gone, then disable safe mode.
- Deactivate all plugins.
- Activate plugins one by one and check.
- Hopefully you can find the conflicted plugin!
- Make sure the theme files exist.
- Check the structure of your permalinks.
- Edit in incognito mode with your browser.
- Check PHP version of your hosting.