Error using feval in actxserver​('VISSIM.v​issim.800'​)

I want to run vissim 8 using matlab 2015a:

   actxserver('VISSIM.vissim.800')

here is the error:

Server Creation Failed: Server execution failed

Error in actxserver (line 86)
        h=feval(['COM.' convertedProgID], 'server', machinename, interface);

it is fine when I am using vissim7! I would be thankful for any advice.

[Sogand Karbalaieali]

The problem is solved by registering com server in vissim8.steps: open vissim8 > Help> Register COM server