Webfig MSCHAPv2 Authentication with Cisco ACS

Hi folks,

I would like to ask about webfig authentication using MSCHAPv2 through Cisco ACS v5.7.

Conditions :
I have Cisco ACS v5.7 as a radius integrate with Windows AD 2012R2 as an External Identity Source. I also have mikrotik (mikrobits dinara) with router OS v6.33.

Symptom :
When I’m trying to connect using SSHv2 with putty, everythings work like a charm. But when I’m trying to connect using webfig, suddenly an error message appear says “Internal Server Error”.
mikrotik%20webfig.PNG
Workaround :
I’ve been looking on Cisco ACS log report, but everything works fine. Authentication using MSCHAPv2 was sucessful.
mikrotik cisco acs.PNG
Does anyone have experiencing this issue ? Please let me know.
I do really appreciate it.