External attachments not showing in other computer? #99314

https://thebrain.zendesk.com/agent/tickets/99314?brand_id=169034

Hello David,

Thank you for the detailed explanation. You’re not doing anything wrong here, and this isn’t related to Copilot.

What you’re seeing comes down to the difference between local file links and cloud-accessible links, and how desktop and mobile apps are allowed to access files.

When you use “Link to File” on the desktop, TheBrain is creating a reference to a local file path on your computer, even if that file lives inside a OneDrive-synced folder. Mobile apps (Android and iOS) cannot access local file paths from your desktop machine, so those attachments won’t open on mobile. That behavior is expected.

When you use a OneDrive sharing link instead, that works on mobile because it’s a web-accessible URL. On desktop, whether that same link opens reliably can depend on your OneDrive sign-in state, how the link was shared, and whether authentication is required. That’s why you may sometimes see a permission or “something went wrong” message on desktop even though the link works on mobile.

This also explains why the “Link to File” option is not available in the mobile app. Mobile platforms don’t allow apps to maintain persistent links to arbitrary local files outside the app’s own storage, so the mobile app intentionally only supports uploading files into the Brain or linking via a URL.

One important note: OneDrive (or any third-party cloud sync service) should never be used to sync your actual Brain data folder. Allowing OneDrive to sync the Brains directory can lead to database corruption and sync issues. If you are using OneDrive, it should only be for storing external files that you link to, not for syncing the Brain itself.

As a general guideline, if you need an attachment to work on both desktop and mobile, the best approach is to use a cloud sharing URL (such as OneDrive) or upload the file directly into the Brain. The “Link to File” option is best used for files you expect to access only on the desktop.

Best regards,

John