and so many more things to check …
- is the AP/Hotspot IP address in the User Manager “router” list ?
- RADIUS server IP in the Radius setting? Shared Secret OK ?
- using port UDP/1812? IP path/route OK? Port accessible? (Firewall settings)
- reverse IP route RADIUS->Hotspot OK?
Does RADIUS server respond on NTRadPing or other radius tester?
http://forum.mikrotik.com/t/radius-server-is-not-responding/152803/7