This backup file is damaged and can’t be imported. Try downloading or transferring the file again.
Reason: File integrity check failed (CRC mismatch).
What does this mean?
When All-in-One WP Migration creates a backup of your website, it also saves a unique fingerprint (called a checksum) of the file. Think of it like a seal on an envelope — if the seal is broken when the letter arrives, you know something went wrong during delivery.
When you try to import the backup, the plugin checks whether the file still matches its original fingerprint. If it doesn’t match, it means the file was changed or damaged at some point between when it was created and when you tried to import it. The plugin stops the import to protect your website from restoring corrupted data.
What usually causes this?
- Incomplete download — The file didn’t fully download due to a dropped internet connection, browser timeout, or server interruption.
- Transfer corruption — The file was damaged while being moved between computers, external drives, or cloud storage services (Google Drive, Dropbox, etc.).
- FTP/SFTP issues — The file was uploaded to the server in text mode instead of binary mode, or the transfer was interrupted.
- Disk or storage errors — The drive where the backup is stored has bad sectors or filesystem issues.
- File size limits — Your hosting provider or server silently truncated the file because it exceeded an upload size limit.
- Browser or plugin interference — A browser extension, proxy, or security plugin modified the file during download or upload.
How to fix it
Download the backup file again
Go back to the source site (the site you exported from) and create a fresh export, or re-download the existing backup file. Make sure the download completes fully without interruption.
Check the file size
Compare the size of the file on the source site with the file you downloaded. They should match exactly. If the downloaded file is smaller, the download was incomplete.
Use binary mode for FTP/SFTP transfers
If you’re transferring the .wpress file via FTP, make sure your FTP client is set to Binary transfer mode (not ASCII or Auto). This prevents the file from being altered during transfer.
Avoid cloud storage modifications
Some cloud storage services can modify files (for example, Google Drive may convert file formats). Download the backup directly from the source site whenever possible instead of passing it through intermediate storage.
Try a different browser or disable extensions
Download managers, ad blockers, or security extensions can sometimes interfere with large file downloads. Try downloading in an incognito/private window, or use a different browser.
Check server upload limits
If you’re uploading a large backup, your server may silently truncate the file. Check your hosting control panel or ask your hosting provider about the maximum upload size. You may need to increase upload_max_filesize and post_max_size in your PHP settings.
Quick fix for most cases:
Re-export the backup from the source site, download it directly to your computer without interruption, and import it immediately to the destination site. This eliminates most transfer-related corruption.
If you’ve tried all the steps above and are still seeing this error, please contact support for further assistance.