Why won't the extension link to the desktop app?

Check these first

The desktop app is open, unlocked, and showing the Connect a browser window.
Both the desktop app and the extension are up to date.
If you installed the browser after the desktop app, quit and reopen the desktop app.

Message	What to do
Open Connect a browser in the desktop app, then try again.	In the desktop app, open Settings → Sync and choose Connect, then press Link again.
This browser cannot reach the desktop app yet.	Quit and reopen the desktop app, then try again.
Could not reach the desktop app.	Make sure the desktop app is installed and open, then try again.
Bramble needs that permission to talk to the desktop app.	Choose Allow and continue and accept the browser’s prompt.
Permission needed	The browser’s permission was turned off. Choose Allow again.
The symbols did not match, so nothing was linked.	Start again from Connect a browser in the desktop app.
The desktop app did not approve the link.	Choose Approve in the desktop app when the symbols match.
That link is no longer in progress.	More than 3 minutes passed. Start again from Connect a browser.
The desktop app didn’t send its vault.	Keep the desktop app open and unlocked, then choose Try again.
Linking didn’t finish. Link again.	Start again from Connect a browser.
This vault’s entries didn’t copy into the desktop’s vault. They are still in the old vault.	Nothing was lost. Link again to retry.
The desktop app did not accept that code.	The desktop app is an older version. Update it, then link again.

Message	What to do
Connecting a browser needs a master password.	Turn one on in Settings → Security, then choose Connect again.
The browser was not linked.	The browser stopped before linking finished. Start again from Connect.