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WordPress white screen cache or propagation drift response

A WordPress cache or propagation drift note for white screen: WordPress failure caused by plugin fatal error, REST route block, database credentials, object cache, or WP-Cron loop. It includes evidence, output examples, branches, and the smallest reliable fix.

highwhite screen5 min read
First command
grep -R "white screen" ./logs
First evidence

Treat white screen as a cache or propagation drift case. First collect evidence for browser cache, CDN cache, DNS TTL, panel propagation, and stale application cache.

Search queries
WordPress white screenWordPress error white screenWordPress white screen cache or propagation drift response

When this happens

Use this when the panel says fixed but some users still see the old error. Do not stop at the screen message; validate browser cache, CDN cache, DNS TTL, panel propagation, and stale application cache first.

Symptom checklist

  • white screen appears repeatedly in the WordPress UI or logs.
  • debug.log, plugin list, permalink, PHP memory differs between successful and failed requests.
  • The issue appears only after separating WordPress core from plugin/theme code.
  • It often follows deploys, permission changes, configuration edits, or data refreshes.

Likely causes

  • white screen specifically changes the investigation surface for WordPress: verify the exact failing object, route, user, and timestamp before applying the broader pattern.
  • A plugin or theme throws a PHP fatal error before WordPress can render the page.
  • Security, permalink, or server rewrite rules block REST API routes.
  • wp-config.php database credentials or host differ from the active database.
  • Object cache serves stale options after a migration.
  • WP-Cron is disabled, blocked by loopback, or duplicated with system cron.
  • For the cache or propagation drift case, the first useful clue is browser cache, CDN cache, DNS TTL, panel propagation, and stale application cache.

First 1-minute checks

  1. Write down the first failure time, latest change, affected user, path, and object ID.
  2. Compare debug.log, plugin list, permalink, PHP memory for success and failure in the same window.
  3. Test the hypothesis: WordPress failure caused by plugin fatal error, REST route block, database credentials, object cache, or WP-Cron loop.
  4. Classify this as cache or propagation drift: browser cache, CDN cache, DNS TTL, panel propagation, and stale application cache.
  5. Capture current values before changing configuration.

First evidence

Treat white screen as a cache or propagation drift case. First collect evidence for browser cache, CDN cache, DNS TTL, panel propagation, and stale application cache.

Output examples

Normal output

Fresh requests and DNS answers show the same intended value from multiple networks.

Failing output

Only one resolver, browser, CDN edge, or cached object still returns the old value.

Output-to-action branches

  • The panel says fixed but some users still see the old error.
    Separate DNS, CDN, browser, and application cache, then purge only the stale layer.
  • The working and failing outputs differ.
    Act on the differing layer first: For white screen, apply the fix only after reproducing the same condition and saving the before/after evidence for this exact code.
  • Command output is normal but users still fail.
    Separate browser cache, cookies, permissions, and network location before declaring it fixed.

Do not do this

  • Do not repeatedly edit correct DNS records just because a stale resolver is still visible.
  • Do not change multiple layers before identifying the failing layer.
  • Do not delete production data, grant broad permissions, or disable security controls as a first response.

Evidence quality

Auto-generated operator draft: includes issue-specific causes, commands, output branches, and unsafe-action warnings. Official-source links and real incident validation are queued for enrichment.

Commands to run first

grep -R "white screen" ./logs
wp plugin list
wp theme list
tail -n 200 wp-content/debug.log
wp rewrite flush --hard
wp plugin list --status=active || true
wp theme list || true
wp option get siteurl || true
grep -R "PHP Fatal\|REST\|database connection\|wp-cron" wp-content/debug.log ./logs
curl -I https://example.com -H 'Cache-Control: no-cache' && dig +trace example.com

Fix order

  1. Record the full white screen message, failing URL, user, object ID, and latest change.
  2. Collect issue-specific evidence for WordPress failure caused by plugin fatal error, REST route block, database credentials, object cache, or WP-Cron loop.
  3. Compare the failing case with a successful case before editing settings.
  4. If this is the cache or propagation drift branch, Separate DNS, CDN, browser, and application cache, then purge only the stale layer.
  5. Re-check with the same command and URL, then record the normal output.

Actions by cause

  • For white screen, apply the fix only after reproducing the same condition and saving the before/after evidence for this exact code.
  • Enable WP_DEBUG logging temporarily and identify the first plugin or theme fatal error.
  • Flush permalinks and verify REST routes through the web server.
  • Check database host, user, password, and table prefix in wp-config.php.
  • Clear object cache after moving domains or databases.
  • Use one cron mechanism and verify loopback requests succeed.
  • For the cache or propagation drift branch, Separate DNS, CDN, browser, and application cache, then purge only the stale layer.

Verification metadata

  • operator-draft
  • official-reference-linked
  • 2026-07-23

Update queue

  • Review cadence
    weekly-source-review
  • Next enrichment
    Add one official-source check and one real output example for WordPress white screen.

Environment-specific checks

  • Shared hosting, proxies, VPNs, or CDN layers can change WordPress core from plugin/theme code results.
  • Do not trust only the WordPress UI; compare command output.
  • Japanese hosting panels may show completion before DNS or SSL fully propagates.
  • Test from both office and external networks.

Prevent it next time

  • Store normal examples for debug.log, plugin list, permalink, PHP memory.
  • Add plugin isolation, permalink flush, PHP limit tuning to the release checklist.
  • Keep recurring errors in the same note format.
  • Split alerts by error rate, latency, certificates, disk, and permission changes.