Fixes for the issues people hit most often. Find your symptom below and work through the steps in order.

The DB Optimizer screen won’t load, or shows up blank

The screen is a single-page app that talks to your site over the WordPress REST API. A blank or stuck screen usually means that connection is being blocked.

Try these in order:

1. Hard refresh the page. Reload with the cache bypassed (Ctrl+Shift+R on Windows, Cmd+Shift+R on Mac).
2. Check for a REST API block. Some security plugins, firewalls, and host rules switch the WordPress REST API off. Temporarily turn that protection off, or add an exception for the `dupdbopt/v1` routes, then reload.
3. Look for JavaScript errors. Open your browser console (F12). An error coming from another plugin or your theme can stop the app rendering. Try again with your other plugins temporarily disabled.
4. Check you’re logged in as an administrator. DB Optimizer is an admin-level tool.

I get a security or “nonce” error after leaving the tab open a while

The plugin refreshes its security token on its own while the tab is active. But if the page sat idle for a long stretch, the token can still expire.

Fix: Reload the page. A fresh load hands you a new token and the error clears.

A cleanup count won’t drop to zero

This one’s expected on big sites, not a bug. Each cleanup type only processes so many items per run, so the request stays quick.

Fix: Run the cleanup again, and keep going until the count clears.

I cleaned revisions (or trashed items) but some are still there

Items newer than your retention window are protected on purpose.

Fix: If you want the more recent ones gone too, lower the retention window in Settings and run the cleanup again. See Configuring the Retention Window. Back up first, as always.

A table optimize or repair comes back “Failed”

A failed result points to something on the server side rather than the plugin itself.

Try these in order:

1. Wait a moment and retry. Another process may have had the table locked for a second.
2. Check database permissions. Your database user needs permission to run OPTIMIZE and REPAIR. Some managed hosts restrict this, and your host can confirm.
3. Check disk space. Optimizing a large table needs temporary working room. A full disk can cause a failure.
4. If it keeps happening, contact support with the exact table name and the message you saw.

A table repair comes back “Unsupported”

This isn’t an error. The table runs on the InnoDB storage engine, which doesn’t support the manual REPAIR command. InnoDB takes care of itself with built-in crash recovery, so there’s nothing for you to do. See Managing Database Tables.

My license won’t activate

1. Re-copy the key. Check there are no stray spaces before or after it.
2. Check your activation limit. The key may already be active on its maximum number of sites. Deactivate it on a site you’ve retired, or check your account at https://duplicator.com/my-account/.
3. Check outgoing connections. Activation needs to reach https://duplicator.com. If your server or a security plugin blocks outgoing requests, it’ll fail. Ask your host to allow connections to duplicator.com.

The backup warning banner won’t go away

The banner on the Cleanup tab shows up when Duplicator Pro reports no backup, or a backup that’s getting old.

Fix: Take a fresh backup in Duplicator Pro and confirm it finished. The banner clears once a recent backup turns up. If you don’t use Duplicator Pro, the banner doesn’t apply to you.

Still stuck?

Open a ticket at https://duplicator.com/my-account/support/. To help us sort it out faster, include:

• Your WordPress and PHP versions
• Your DB Optimizer version
• The exact error message, or a screenshot
• What you were doing when it happened (which tab, which action)