WordPress white screen first triage response

When this happens

Use this when only the visible message is known. Do not stop at the screen message; validate the first observable mismatch before any setting is changed 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 first triage case, the first useful clue is the first observable mismatch before any setting is changed.

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 first triage: the first observable mismatch before any setting is changed.
5. Capture current values before changing configuration.

First evidence

Treat white screen as a first triage case. First collect evidence for the first observable mismatch before any setting is changed.

Output examples

Normal output

No matching error appears during the affected request window.

Failing output

The same error appears at the exact request time with the affected path, user, or object.

Output-to-action branches

• Only the visible message is known.
  Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.
• 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 change DNS, SSL, cache, and permissions at the same time.
• 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

date -u && grep -R "ERROR\|WARN\|failed" ./logs | tail -n 50

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 first triage branch, Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.
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 first triage branch, Collect timestamp, route, request ID, user, and the first backend log line before editing configuration.

Evidence links

• WordPress debugging official
• WP-CLI handbook official

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.

Related notes

• WordPress white screen after plugin update
• WordPress 500 first triage response
• WordPress plugin conflict first triage response
• WordPress theme error first triage response
• WordPress permalink first triage response
• WordPress REST API first triage response
• WordPress upload limit first triage response
• WordPress database connection first triage response