This issue will be resolved permanently in upcoming HC9 build 09.
Temp Solution:
By adding a registry entry named “WebRoot” in ME registry paths will resolve this problem.
HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Services\WebAdmin
HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Services\WEBMAIL
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mail Enable\Mail Enable\Services\WebAdmin
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mail Enable\Mail Enable\Services\WEBMAIL