You noticed that Client machine that should connect via CEM are not connecting to Internet Gateway.
From the IGW logs you will find a entry like: "The request Performance Counter is not a custom counter, it has to be initialized as ReadOnly"
ITMS 8.8.1
Unknown currently
CMD <SMP Internet Gateway install path>\InternetGtwMngrCmd.exe -counters (run cmd.exe under admin account, go to SMP Gateway installation folder and run InternetGtwMngrCmd.exe -counters)