Accpepted ciphers were changed in 7.37 to the following:
Since RC4 is the only cipher available on that server the connection fails, you can remove the RC4 exclusion from the string to connect to this host. Add the following line to the [ssl]
section of mirc.ini:
I'd blame the server more than mIRC for offering such weak security, but this situation could be presented to the user more clearly.