Mikrotik RB1100 User Manager Problem IN (5.19-5.20)

Hello ,

I have A Problem with User Manager In RB1100 , around 2 years I’m configuring RB1100 it was worked fine , but lately when I’m trying to activate User manager ,Usually I’m creating User for clients , when I’m trying to login with hotspot it tells me Radius server is not responding.

any idea ??