Troubleshooting
Fix Corrupt Zip Or Archive Multisite
Diagnose and resolve corrupt zip or archive multisite during WordPress Multisite backup or restore with Multisite Migrate.
Free
Fix: Fix Corrupt Zip Or Archive Multisite
When you hit corrupt zip or archive multisite, start with the Multisite Migrate job log: last completed chunk, PHP/memory messages, HTTP 502/504, disk/inode errors, or cloud auth failures. Multisite archives are larger and table-heavier than single-site jobs, so shared hosts interrupt long PHP requests — Jobs in Chunks exist specifically for that.
Check tmp/disk free space, upload_max_filesize for imports, S3/Drive/Dropbox/SFTP credentials for Plus uploads, and security plugins that block admin-ajax. After restore issues, verify siteurl/home, rewrite rules, domain mapping (sunrise.php), object-cache drop-ins, and CDN caches. Reproduce once on Staging before changing production limits.
Log-first diagnosis for “Corrupt Zip Or Archive Multisite”
Separate backup failures from post-restore URL/media/login problems. Capture job percent, last log line, HTTP status, hosting class, and whether a local archive already exists. That evidence decides whether you raise PHP limits, free disk, fix cloud auth, or only re-upload.
For “corrupt zip or archive multisite”, avoid restarting from scratch if a chunked job can resume. Lost locks, cleared tmp, or a new job ID are common reasons a progress bar jumps back to 0%.
Fixes that match Multisite reality
Raise PHP time/memory enough for safety, but keep chunked jobs — shared hosts can still kill long workers. Free disk and inodes before large network archives. Allow admin-ajax through WAF or security plugins. On Plus, re-test Drive/Dropbox/S3-compatible/SFTP credentials and quotas.
Free handles core backup/restore; Plus covers BYO cloud; Pro covers remote import, empty-server installer, Staging, and split/extract. Pick the tool that matches the failure — do not upgrade tiers hoping a cloud auth typo will disappear.
After the archive completes
If the local archive is good, you can restore even when cloud upload failed. Fix destination auth/quota, then re-upload, or restore from local. On Staging, confirm HTTPS, mapping, media, and logins before production.
If mid-restore failed, do not “fix” production DNS first — finish Staging validation and confirm table/prefix expectations.
Retention, encryption, and support hygiene
For fix corrupt zip or archive multisite, keep enough archive generations to roll back a bad deploy or failed migration. Optional .venc AES-256 encryption on Multisite Migrate archives protects copies at rest when you store offsite on Plus destinations. Document credentials, schedule windows, and who may run Network Admin jobs.
Separate schedule failures from restore failures in your runbook so on-call staff do not rebuild a finished archive unnecessarily.
Why this matters
Log-first diagnosis
Identify whether the failure is PHP, disk, DB, cloud, or URL rewrite.
Chunking as the default fix
Resume instead of restarting huge Multisite jobs from zero.
Restore-side checks
Separate backup failures from post-restore URL/media/login issues.
Support-ready evidence
Know which log lines and environment facts to capture for support.
Steps
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1Capture the failure point
Record job percent, last log line, HTTP status, and hosting type for “corrupt zip or archive multisite” before changing settings.
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2Apply the matching fix
Raise safe limits, free disk, fix credentials, or allow AJAX through WAF — based on the log, not guesswork.
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3Re-run chunked
Resume the job. Avoid overlapping schedules that collide on locks or wipe tmp mid-run.
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4Confirm local archive integrity
If the archive finished, note its size/path. Cloud upload can be retried separately from rebuilding Multisite tables.
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5Validate restore path
Test import/restore on Staging. Check URLs, media, logins, and mapping before production changes.
Frequently asked questions
Quick answers for this Multisite backup topic. Still stuck? Open the docs or contact support.
Should I raise PHP limits forever?
Raise them enough for safety, but keep chunked jobs — shared hosts can still kill long workers.
Why did the job restart at 0%?
Often tmp cleanup or a new job ID. Confirm the previous lock is gone before starting again.
Cloud upload failed but local archive exists?
Repair cloud credentials or quota, then retry upload — or restore from the local archive.
Is “corrupt zip or archive multisite” usually backup or restore?
Split the problem: job log for backup failures; Staging URL/media/login checks for restore failures.