While opening AX error is occured "Server has reached its memory limit, Please contact your administrator"

Dear All,

While opening AX on Client as well as on Server am getting the following error ."Server has reached its memory limit, Please contact your administrator"          

I increased the Max Buffer size from 24 to even 100 too. Restarted Service and Server, even though am getting the same.

Can some one help to Solve this error.

Thanks,

Ansar.