OOO: Client Certificate Mismatch

Other messages might be displayed (depending on version):

“Terminal Not Registered”, see also: Error: Terminal is not registered
“TLS error”

Your BATM connects to the server (CAS) over the Internet using an encrypted and secure channel. To identify itself to the server, the BATM presents a pre-authorized fingerprint to the server. If this fingerprint changes for any reason, the server will refuse to converse with the BATM, and the error message above will be displayed. You should also note the error in the affected Terminal’s Event Log.

The authorization process is called "pairing", and is a discrete step performed when the BATM is put into service. Typically, this process is only done once, and is automatic that first time only.

This is a security measure.

Pairing will fail after a 10 minute window has expired.
Turn the BATM “on” and connect to CAS within ten minutes of an attempted pairing.
See: https://generalbytes.atlassian.net/wiki/x/DgCOsQ

Something changed, and now you see this message. Don't fret. This is easily resolved in one of two ways:

GUI instructions:

1. Navigate to your Terminal.

2. Click “Unpair Terminal”:

3. Re-pair the Terminal

See: Terminal Pairing - General Bytes Knowledge Base - Confluence

CLI instructions:

1. Note the BATM serial number (e.g. BT101308) for step 3 (serialno).

2. Tell CAS to forget the old fingerprint:

sudo /batm/batm-manage terminal-unpair serialno

3. Turn the BATM back on.

After booting, the BATM will again attempt to connect to CAS.

CAS will now reauthorize the BATM’s fingerprint.
The problem should not normally recur.
The error should disappear within 15 minutes.