Message
Could not start the tunnel: the core refused
Could not start the tunnel: the core refused: what the ForestVPN message ne.quantum_start means, why it appears and what to do about it.
Updated October 11, 2026
The app says: "Couldn't start the tunnel."
What it means
The part of ForestVPN that builds the tunnel refused to start.
What to do
Try again, up to three times. If it still fails, use Report a problem in the app.
Why it happens
The core checks its settings before it starts, and one of them was not usable on this device.
Where you see it
The ForestVPN apps show this message on the connection screen, and in a notification when it affects your connection. The code is ne.quantum_start.