Fix Dropbox connection errors

Most connection problems come from three things: a Redirect URI that does not match exactly, permissions not saved on Dropbox, or a security setting on the site or the hosting. The Check the connection button in Dropbox Documents > Dropbox connection usually tells you which one.

"Invalid redirect_uri"

Dropbox shows this when the address sent by the plugin is not registered in your app.

1. In Dropbox Documents > Dropbox connection, open The connection fails: what to check at the bottom. It shows the exact Address this site sends.
2. In the Dropbox App Console, Settings tab, Redirect URIs, compare it character by character. The usual differences: www present on one side only, http instead of https, a trailing slash.
3. Add the exact value with Add and try Connect Dropbox again.

If your site answers on more than one address (with and without www, staging copies, a reverse proxy), you can fix the value in wp-config.php. The plugin shows the exact line to copy, which looks like:

define( 'LRDBP_REDIRECT_URI', 'https://yoursite.com/wp-admin/admin.php?page=lr-dropbox-portal&lrdbp_oauth=callback' );

Permission (scope) errors or empty folders

If the check says "The Dropbox app is missing these permissions", or the Browse button shows nothing:

1. Open your app on dropbox.com/developers/apps, Permissions tab.
2. Tick account_info.read, files.metadata.read and files.content.read.
3. Click Submit at the bottom of the page.
4. Back in WordPress, click Disconnect in Dropbox connection, then Connect Dropbox again. This step is required: the connection keeps the permissions it was created with.

"Your account is connected, but Dropbox is not answering"

The Dropbox connection screen shows a red Not working label when the site has a saved connection but Dropbox refuses it. This happens when the app was deleted or recreated, the App secret changed, or access was revoked from Dropbox. Check the App key and App secret (open Your Dropbox app, step 4), click Disconnect and try again, then connect again.

"The server cannot reach Dropbox"

Your hosting blocks outgoing connections. This is not a plugin setting: ask your hosting provider to allow HTTPS connections to api.dropboxapi.com (and content.dropboxapi.com for downloads).

"Security check not passed. Try connecting again."

The connection took too long (more than 15 minutes) or was started in another browser. Click Connect Dropbox again and complete it right away.

Folders load but files do not open

Files are delivered through wp-admin/admin-post.php. Some security plugins block /wp-admin/ for users who are not administrators. Add an exception for admin-post.php in that plugin.

Dropbox Business team spaces

Team folders mounted in the connected account are visible. Team spaces with their own namespace are not supported in this version: the check reports that Dropbox "rejects the requested path".