'Timeout' error on the 802.1X test in Dashboard

1. The Access-Request message from the Meraki AP never reached the RADIUS server, or 
2. The reply (Access-Accept or Access-Reject) from the RADIUS server never reached the AP

- Check the RADIUS logs to see if the Access-Request ever came in from the Meraki AP and/or whether there are any errors
- Perform wired packet captures to see where the request and reply packets are going (or not going).